Toasted Marshmallow Cake

This Toasted Marshmallow Cake layers tender vanilla sponge with a gooey marshmallow fluff filling, clouds of smoky toasted marshmallow buttercream made from real toasted marshmallows, and a halo of torched mini marshmallows and graham cracker crumbs on top. It captures all the cozy campfire vibes of a s’more, but keeps the focus firmly on marshmallow and graham cracker (no chocolate in sight).

Quick Recipe Version (TL;DR)

• Yield: 12 servings
• Prep Time: 45 minutes
• Cook Time: 35 minutes
• Total Time: About 3 hours (including cooling and decorating)

Quick Ingredients

• 2 3/4 cups (330 g) all-purpose flour
• 2 1/2 tsp baking powder, 1/2 tsp baking soda, 3/4 tsp fine salt
• 1 cup (226 g) unsalted butter + 2 cups (400 g) granulated sugar
• 4 large eggs, 1 Tbsp vanilla extract
• 1 1/3 cups (320 ml) buttermilk + 1/3 cup (80 g) sour cream
• 4 cups (about 200 g) mini marshmallows for frosting + 2 cups (about 100 g) for topping
• 1 1/2 cups (339 g) unsalted butter for frosting
• 4 1/2 cups (540 g) powdered sugar, 1/4 tsp salt, 2 tsp vanilla, 3–4 Tbsp heavy cream
• 1 (7–7.5 oz / about 200 g) jar marshmallow creme
• 1 cup (about 100 g) graham cracker crumbs

Do This

• 1. Heat oven to 350°F (175°C). Grease and line three 8-inch round cake pans. Whisk together flour, baking powder, baking soda, and salt.
• 2. Cream 1 cup butter with sugar until light and fluffy. Beat in eggs one at a time and vanilla. Alternate adding dry ingredients with buttermilk mixed with sour cream, just until smooth.
• 3. Divide batter among pans and bake 25–30 minutes until golden and a toothpick comes out clean. Cool in pans 10 minutes, then on racks until completely cool.
• 4. Broil 4 cups mini marshmallows on a lined baking sheet until deeply toasted. Cool. Beat 1 1/2 cups butter with powdered sugar, salt, vanilla, and cream, then beat in toasted marshmallows to make buttercream.
• 5. Level cakes. Place first layer on a board; pipe a ring of buttercream around the edge and fill the center with half the marshmallow creme. Repeat with second layer and remaining creme; top with third layer.
• 6. Crumb-coat and then fully frost cake with toasted marshmallow buttercream. Press graham cracker crumbs onto the sides, pile remaining mini marshmallows on top, and toast them with a kitchen torch until golden.

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Why You’ll Love This Recipe

• All the nostalgic, campfire-toasted marshmallow flavor in a showstopping layer cake, without any chocolate.
• Real toasted mini marshmallows whipped into the buttercream for authentic smoky, caramelized sweetness.
• Soft vanilla cake, gooey marshmallow fluff filling, and crunchy graham cracker crumbs for amazing texture contrast.
• Clear, step-by-step directions make this bakery-style cake completely doable for home bakers.

Grocery List

• Produce: None.
• Dairy: Unsalted butter, buttermilk, sour cream, heavy cream, eggs.
• Pantry: All-purpose flour, granulated sugar, powdered sugar, baking powder, baking soda, fine salt, vanilla extract, mini marshmallows, marshmallow creme/fluff, graham crackers, nonstick baking spray or butter and flour for pans.

Full Ingredients

For the Vanilla Cake Layers (three 8-inch rounds)

• Nonstick baking spray or butter and flour, for greasing pans
• 2 3/4 cups (330 g) all-purpose flour, spooned and leveled
• 2 1/2 tsp baking powder
• 1/2 tsp baking soda
• 3/4 tsp fine sea salt
• 1 cup (226 g) unsalted butter, softened to room temperature
• 2 cups (400 g) granulated sugar
• 4 large eggs, at room temperature
• 1 Tbsp pure vanilla extract
• 1 1/3 cups (320 ml) buttermilk, at room temperature
• 1/3 cup (80 g) sour cream, at room temperature

For the Toasted Marshmallow Buttercream

• 4 cups (about 200 g) mini marshmallows
• 1 1/2 cups (339 g) unsalted butter, softened to room temperature
• 4 1/2 cups (540 g) powdered sugar, sifted if lumpy
• 1/4 tsp fine sea salt
• 2 tsp pure vanilla extract
• 3–4 Tbsp heavy cream, at room temperature (plus a little more if needed)

For the Marshmallow Fluff Filling

• 1 (7–7.5 oz / about 200 g) jar marshmallow creme or fluff (about 2 1/4 cups), at room temperature

For Decorating

• 2 cups (about 100 g) mini marshmallows
• 6 full graham cracker sheets, finely crushed (about 1 cup / 100 g graham cracker crumbs)
• Optional: a little extra powdered sugar or heavy cream to fine-tune frosting consistency

Step-by-Step Instructions

Step 1: Prepare the pans and preheat the oven

Preheat your oven to 350°F (175°C). Position the racks so that the three cake pans can sit in the center of the oven; if they will not fit on one rack, plan to bake two layers and then the third.

Grease three 8-inch round cake pans generously with nonstick baking spray, or butter them well and dust lightly with flour, tapping out any excess. For easy release, line the bottom of each pan with a circle of parchment paper. Set the prepared pans aside.

Step 2: Make the vanilla cake batter

In a medium bowl, whisk together the flour, baking powder, baking soda, and salt until well combined. This helps distribute the leavening evenly so the cake rises uniformly.

In the bowl of a stand mixer fitted with the paddle attachment (or in a large bowl with a hand mixer), beat 1 cup (226 g) softened butter on medium speed for about 1 minute. Add the 2 cups (400 g) granulated sugar and cream together on medium-high speed for 3–4 minutes, until the mixture is very light and fluffy.

Beat in the eggs one at a time, mixing well after each addition and scraping down the sides of the bowl as needed. Mix in the 1 Tbsp vanilla extract.

In a measuring jug or small bowl, whisk together the buttermilk and sour cream. With the mixer on low speed, add the dry ingredients in three additions, alternating with the buttermilk mixture: add one-third of the flour mixture, half the buttermilk mixture, another third of the flour, the remaining buttermilk, and finally the last third of the flour. Mix just until the batter is smooth with no dry streaks. Do not overmix or the cake may become dense.

Step 3: Bake the cake layers and cool completely

Divide the batter evenly among the three prepared pans. If you want to be precise, you can weigh the filled pans; they should each contain about the same amount of batter. Smooth the tops with an offset spatula.

Bake at 350°F (175°C) for 25–30 minutes, until the cakes are lightly golden, the edges are just pulling away from the sides of the pans, and a toothpick inserted into the center comes out clean or with a few moist crumbs.

Cool the cakes in their pans on a wire rack for about 10–15 minutes. Run a thin knife around the edges, then carefully turn the layers out onto the rack. Peel off the parchment and let the cakes cool completely, at least 1 hour. For easiest assembly, wrap the cooled layers in plastic wrap and chill them in the refrigerator for 30–60 minutes to firm up slightly.

Step 4: Toast the marshmallows for the buttercream

While the cakes cool, toast the marshmallows for the frosting. Move an oven rack so it is about 6 inches (15 cm) beneath the broiler element. Line a baking sheet with parchment paper and lightly grease the parchment to help prevent sticking.

Spread 4 cups (about 200 g) mini marshmallows in an even layer on the prepared baking sheet. Turn the broiler on high and place the baking sheet under the broiler. Watch constantly and do not walk away: the marshmallows will go from pale to deeply toasted in 1–2 minutes. Rotate the pan as needed for even browning.

When the marshmallows are a deep golden brown with some darker, toasty spots, remove the tray from the oven. Let the toasted marshmallows cool completely (about 10–15 minutes). They will sink and solidify into a sticky sheet. Lightly oil a spatula if needed to help lift them later.

Step 5: Make the toasted marshmallow buttercream

In the bowl of a stand mixer fitted with the paddle attachment (or with a hand mixer), beat 1 1/2 cups (339 g) softened butter on medium-high speed for 2–3 minutes, until creamy and slightly paler in color.

Reduce the speed to low and gradually add the powdered sugar and 1/4 tsp salt, about 1 cup at a time, mixing until just combined before adding more. Once all the sugar is in, add the 2 tsp vanilla and 3 Tbsp heavy cream. Turn the mixer up to medium-high and beat for 3–4 minutes, until the buttercream is light and fluffy. If it seems too stiff, add another 1 Tbsp cream; if it is too soft, beat in a bit more powdered sugar.

Using a lightly oiled spatula or your hands, break the cooled sheet of toasted marshmallows into chunks and add them to the buttercream. Beat on medium-high speed for 1–2 minutes, until the marshmallows are mostly incorporated. A few visible flecks and strands of toasted marshmallow are fine and add lovely texture and flavor.

Step 6: Fill and stack the cake with marshmallow fluff

If your cake layers have domed tops, level them with a long serrated knife so they stack neatly. Place a small dab of buttercream in the center of your cake board or serving plate and set the first layer on top to anchor it.

Transfer a portion of the toasted marshmallow buttercream to a piping bag fitted with a large round tip (or use a zip-top bag with the corner snipped off). Pipe a thick ring (a “dam”) of frosting around the outer edge of the first cake layer; this will hold in the marshmallow fluff.

Stir the marshmallow creme in the jar to loosen it, then spread about half of it (roughly 1 to 1 1/4 cups) inside the buttercream ring, smoothing it gently to an even layer but not quite to the very edge.

Place the second cake layer on top, pressing lightly. Pipe another ring of buttercream around the edge and fill the center with the remaining marshmallow creme. Top with the third cake layer, placed bottom-side-up for the flattest surface. Press gently to secure, then refrigerate the stacked cake for 20–30 minutes to let the filling firm up before you frost the outside.

Step 7: Frost, decorate, and toast the top

Using an offset spatula, spread a thin layer of toasted marshmallow buttercream over the top and sides of the chilled, stacked cake to create a crumb coat. This traps any loose crumbs. Chill the cake for 15–20 minutes until the crumb coat is set.

Apply a thicker layer of buttercream over the top and sides, smoothing or swirling it to your liking. Reserve a little frosting if you want to pipe decorative swirls on top later. Gently press the graham cracker crumbs onto the sides of the cake (you can cover just the bottom half for a “border” effect or the entire side), letting any excess fall back onto a tray.

Arrange the remaining 2 cups mini marshmallows on top of the cake in a generous mound or in concentric circles, lightly pressing them into the frosting so they adhere. Just before serving, use a kitchen torch to toast the marshmallows to a golden-brown, moving the flame constantly and staying a few inches away to avoid burning.

If you do not have a torch and your cake plate is oven-safe, you can very briefly place the cake under the broiler, watching every second and rotating as needed. Be aware that this method warms the cake more and is a bit riskier; the torch gives you more control. Let the cake sit for a few minutes after toasting, then slice and serve. For the cleanest slices, chill the cake for 20–30 minutes and use a sharp knife wiped clean between cuts.

Pro Tips

• Use room-temperature ingredients. Softened butter, and eggs and dairy that are not cold, help the batter emulsify properly and create a tender, even crumb.
• Do not overmix the batter. Once the flour goes in, mix only until everything is combined. Overmixing develops gluten and can make the cake dense.
• Chill between stages. A short chill after stacking (to firm the fluff) and after the crumb coat (before final frosting) makes the cake much easier to frost neatly.
• Watch the marshmallows under the broiler. They toast very quickly. Keep the oven door slightly ajar and your eyes on them the entire time.
• Adjust frosting consistency as needed. If the toasted marshmallows make the buttercream too sticky or thick, add a teaspoon or two of cream; if it is too soft, beat in a little extra powdered sugar.

Variations

• Sheet cake version: Bake the vanilla batter in a greased and parchment-lined 9 x 13-inch pan at 350°F (175°C) for 32–38 minutes. Cool completely, then spread with a generous layer of toasted marshmallow buttercream, dollop marshmallow creme on top and swirl, and finish with graham crumbs and torched mini marshmallows.
• Cupcake version: Divide the batter among 24 lined muffin cups and bake at 350°F (175°C) for 18–22 minutes. Core each cupcake, fill with a spoonful of marshmallow fluff, top with toasted marshmallow buttercream, sprinkle with graham cracker crumbs, and add a few torched mini marshmallows on each.
• Lightly spiced variation: For a subtle, cozy twist, add 1 tsp ground cinnamon to the dry ingredients in the cake and a pinch of cinnamon to the graham cracker crumbs.

Storage & Make-Ahead

The fully assembled cake can be kept, covered, at cool room temperature for up to 1 day. For longer storage, cover well and refrigerate for up to 3–4 days. The marshmallow fluff and buttercream will firm up in the fridge; let the cake sit at room temperature for 30–45 minutes before serving for the best texture.

You can bake the cake layers up to 2 days ahead. Once completely cool, wrap each layer tightly in plastic wrap and store at room temperature, or freeze for up to 2 months in a freezer bag. Thaw wrapped cakes at room temperature before assembling.

The toasted marshmallow buttercream can be made 1–2 days in advance and stored in an airtight container in the refrigerator. Bring it to room temperature and rewhip for a few minutes before using. For the prettiest finish, toast the marshmallows on top shortly before serving.

Nutrition (per serving)

Approximate values per slice (1/12 of the cake): about 700 calories, 32 g fat (20 g saturated), 105 g carbohydrates, 70 g sugar, 9 g protein, and 360 mg sodium. These numbers are estimates and will vary based on exact ingredients and portion sizes.