Quick Recipe Version (TL;DR)
Quick Ingredients
- 2 1/2 cups (300 g) all-purpose flour
- 2 1/2 tsp baking powder, 1/2 tsp baking soda, 1 tsp fine salt
- 3/4 cup (170 g) unsalted butter, 1 1/2 cups (300 g) light brown sugar
- 3 large eggs, 2 tsp vanilla, optional 1–1 1/2 tsp butterscotch extract
- 1 cup (240 ml) buttermilk, 1/2 cup (120 g) sour cream
- 3/4 cup (130 g) butterscotch chips (or use extract instead)
- 1 1/2 cups (340 g) unsalted butter (for frosting)
- 1 1/4 cups (275 g) light brown sugar total for frosting and sauce
- 3/4 cup (180 ml) heavy cream total (for frosting and sauce)
- 4–5 cups (480–600 g) powdered sugar
- 1/2–3/4 cup toffee bits, pinch of salt, extra vanilla
Do This
- 1. Preheat oven to 350°F (175°C). Grease and line two 8-inch round cake pans with parchment.
- 2. Whisk flour, baking powder, baking soda, and salt. Cream butter and brown sugar; beat in eggs, vanilla (and butterscotch extract if using), then buttermilk and sour cream.
- 3. Mix in dry ingredients until just combined. Fold in butterscotch chips if using. Divide batter between pans and bake 25–30 minutes, until a toothpick comes out clean. Cool completely.
- 4. Make butterscotch sauce: simmer brown sugar, butter, and cream until smooth and slightly thickened. Stir in vanilla and salt; cool to a pourable consistency.
- 5. Make frosting: cook brown sugar with part of the butter and cream until dissolved; cool. Beat remaining butter, then whip in cooled brown sugar mixture, powdered sugar, vanilla, and cream until fluffy.
- 6. Assemble: layer cake with brown sugar frosting between and over the layers. Drizzle with butterscotch sauce and sprinkle with toffee bits and extra chips. Slice and serve.
Why You’ll Love This Recipe
- Deep, cozy butterscotch flavor from brown sugar, butterscotch chips or extract, and homemade sauce.
- Soft, tender golden cake contrasted with rich, fluffy brown sugar buttercream.
- Beautiful presentation with glossy butterscotch drizzle and a crunchy toffee topping.
- Great make-ahead dessert for birthdays, holidays, or any celebration.
Grocery List
- Produce: None
- Dairy: Unsalted butter, buttermilk, sour cream, heavy cream, large eggs
- Pantry: All-purpose flour, light brown sugar, granulated sugar (optional), powdered sugar, butterscotch chips, toffee bits, baking powder, baking soda, salt, vanilla extract, butterscotch extract (optional)
Full Ingredients
Butterscotch Cake Layers (2 x 8-inch rounds)
- 2 1/2 cups (300 g) all-purpose flour
- 2 1/2 tsp baking powder
- 1/2 tsp baking soda
- 1 tsp fine sea salt
- 3/4 cup (170 g) unsalted butter, softened to room temperature
- 1 1/2 cups (300 g) packed light brown sugar
- 3 large eggs, at room temperature
- 2 tsp pure vanilla extract
- Optional for extra flavor or substitution:
- 1 to 1 1/2 tsp butterscotch extract if not using chips or for more intense flavor
- 1 cup (240 ml) buttermilk, at room temperature
- 1/2 cup (120 g) sour cream, at room temperature
- 3/4 cup (130 g) butterscotch chips
- Use these or butterscotch extract, or use both (reduce chips to 1/2 cup if using both).
Brown Sugar Buttercream Frosting
- 1 1/2 cups (340 g) unsalted butter, at room temperature, divided
- 1 cup (220 g) packed light brown sugar
- 1/4 cup (60 ml) heavy cream, plus 1–3 tbsp extra as needed
- 1/2 tsp fine sea salt (reduce to 1/4 tsp if you prefer it less salty)
- 4 to 5 cups (480 to 600 g) powdered sugar, sifted
- 1 1/2 tsp pure vanilla extract
Homemade Butterscotch Sauce
- 4 tbsp (56 g) unsalted butter
- 1/2 cup (110 g) packed light brown sugar
- 1/2 cup (120 ml) heavy cream
- 1 tsp pure vanilla extract
- 1/4 tsp fine sea salt (or to taste)
Topping & Decoration
- 1/2 to 3/4 cup toffee bits (such as English toffee baking bits)
- Extra butterscotch chips, for garnish (optional)
- Pinch of flaky sea salt on top (optional, but lovely with the sweetness)
Step-by-Step Instructions
Step 1: Prep Pans and Preheat the Oven
Adjust an oven rack to the center position and preheat your oven to 350°F (175°C). Grease two 8-inch round cake pans with butter or nonstick spray. Line the bottoms with circles of parchment paper, then lightly grease the parchment as well. This extra step makes it much easier to release the cakes cleanly.
If possible, set out your butter, eggs, buttermilk, and sour cream 30–45 minutes before baking so they come to room temperature. Room-temperature ingredients blend more easily and give you a softer, more even crumb in the finished cake.
Step 2: Mix the Dry and Wet Ingredients for the Cake
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt until well combined. Set aside.
In a large mixing bowl (or the bowl of a stand mixer fitted with the paddle attachment), beat 3/4 cup softened butter and 1 1/2 cups light brown sugar on medium speed for 3–4 minutes, until the mixture looks light, fluffy, and slightly paler. Scrape down the sides of the bowl as needed.
Add the eggs one at a time, beating well after each addition until fully incorporated. Mix in the vanilla extract and, if using extract instead of or in addition to chips, add 1 to 1 1/2 teaspoons butterscotch extract now.
In a measuring cup, whisk together the buttermilk and sour cream until smooth. With the mixer on low speed, add the dry ingredients in three additions, alternating with the buttermilk mixture in two additions (dry, wet, dry, wet, dry). Mix just until the batter is smooth and no dry streaks of flour remain. Do not overmix.
Step 3: Add Butterscotch Chips (If Using) and Bake the Cakes
If using butterscotch chips, toss the 3/4 cup chips with 1 teaspoon of flour in a small bowl to lightly coat them; this helps keep them from sinking. Gently fold the chips into the batter with a spatula.
Divide the batter evenly between the two prepared pans, smoothing the tops with a spatula. Tap each pan firmly on the counter 2–3 times to release any large air bubbles.
Bake for 25–30 minutes, or until the cakes are golden, the edges are just starting to pull away from the sides, and a toothpick inserted into the center comes out clean or with a few moist crumbs (but no wet batter).
Let the cakes cool in their pans on a wire rack for 10–15 minutes. Then run a thin knife around the edges, invert onto the rack, peel away the parchment, and turn the layers right-side up. Allow the cakes to cool completely (at least 1 hour) before frosting.
Step 4: Make the Butterscotch Sauce
While the cakes bake or cool, prepare the butterscotch sauce. In a small saucepan over medium heat, melt 4 tablespoons butter. Add 1/2 cup packed light brown sugar and stir until the sugar looks wet and sandy.
Slowly pour in 1/2 cup heavy cream while whisking constantly. Continue to cook, whisking, until the mixture comes to a gentle simmer. Simmer for 4–5 minutes, whisking occasionally, until slightly thickened and glossy. It will thicken more as it cools.
Remove the pan from the heat and stir in the vanilla extract and salt. Taste carefully (it will be hot) and adjust the salt to your liking. Pour the sauce into a heatproof jar or bowl and let it cool until it is thick but still pourable before using on the cake.
Step 5: Prepare the Brown Sugar Buttercream Frosting
In a small saucepan, combine 1/2 cup (one stick) of the unsalted butter, 1 cup packed light brown sugar, 1/4 cup heavy cream, and the 1/2 teaspoon salt. Place over medium heat and cook, stirring frequently, until the butter is melted and the mixture is smooth and just beginning to bubble around the edges, 2–3 minutes. You want the sugar to dissolve fully so the frosting is not gritty.
Remove from heat and let this brown sugar mixture cool to room temperature. To speed cooling, transfer it to a shallow bowl and stir occasionally. It should be completely cool and slightly thick before you add it to the buttercream, or it may melt the frosting.
In a large bowl, beat the remaining 1 cup (2 sticks) of softened butter on medium-high speed for 2–3 minutes until very light and creamy. Gradually pour in the cooled brown sugar mixture, beating on low at first, then increasing to medium until fully combined and fluffy.
With the mixer on low, gradually add 4 cups powdered sugar, about 1 cup at a time, mixing well and scraping the bowl after each addition. Add the vanilla extract and 1–2 tablespoons extra heavy cream, then beat on medium-high speed for 2–3 minutes until the frosting is smooth, thick, and spreadable. If it is too thick, add more cream 1 teaspoon at a time; if too thin, beat in up to 1 additional cup powdered sugar.
Step 6: Level and Fill the Cake Layers
If the cake layers are domed, use a long serrated knife to gently trim the tops so they are flat. This helps the cake stack evenly and prevents sliding.
Place one cooled cake layer on a serving plate or cake stand, cut side up if you leveled it. Spread about 1 to 1 1/4 cups of the brown sugar frosting evenly over the top, going right to the edges. If you like, drizzle 1–2 tablespoons of cooled butterscotch sauce over the frosting and spread lightly so it stays within the edges and does not drip out.
Top with the second cake layer, cut side down for a smooth top. Press gently to set it in place.
Step 7: Frost the Outside and Chill Briefly
Using an offset spatula, spread a thin layer of frosting (a crumb coat) over the top and sides of the cake to catch any loose crumbs. Chill the cake for 15–20 minutes in the refrigerator to set this layer.
Once the crumb coat is firm, apply the remaining frosting in a thicker, more even layer over the top and sides. You can smooth the frosting for a polished look, or leave it a bit rustic with visible swirls.
Step 8: Finish with Butterscotch Drizzle and Toffee Bits
Ensure the butterscotch sauce is cool but still pourable. If it has thickened too much, warm it very gently in the microwave for a few seconds at a time until it loosens, stirring well. Do not pour it on hot or it can melt the frosting.
Spoon the sauce around the top edge of the chilled, frosted cake, letting some of it gently drip down the sides for a pretty “drip” effect. Pour the remaining sauce into the center and spread lightly to cover the top.
Immediately sprinkle toffee bits over the top, focusing on the outer edge or center, whichever look you prefer. Add a few extra butterscotch chips and a small pinch of flaky sea salt, if using, for contrast and a beautiful finish.
Pro Tips
- Make sure your brown sugar fully dissolves in both the frosting base and the sauce to avoid any grainy texture.
- Cool the cakes completely before frosting; even slightly warm layers can cause the buttercream and sauce to slide off.
- For the neatest slices, chill the fully assembled cake for 30–45 minutes to firm up, then slice with a sharp, warm knife (wipe between cuts).
- If you use butterscotch extract instead of chips, start with 1 teaspoon, taste the batter, and increase up to 1 1/2 teaspoons; it is quite strong.
- Make the butterscotch sauce a little ahead of time so it can cool to the perfect thick-but-pourable consistency by the time you decorate.
Variations
- Salted Butterscotch Cake: Increase the salt in the frosting and sauce slightly and finish the cake with a generous pinch of flaky sea salt on top for a more pronounced sweet-salty contrast.
- 9 x 13 Pan Version: Bake the batter in a greased 9 x 13-inch pan at 350°F (175°C) for 30–35 minutes, then cool and frost the top only. Drizzle with sauce and sprinkle with toffee bits for a simpler, potluck-friendly version.
- Butterscotch Cupcakes: Divide the batter into 24 lined cupcake wells and bake at 350°F (175°C) for 18–22 minutes. Pipe the brown sugar frosting on top, drizzle with cooled sauce, and dust with toffee bits.
Storage & Make-Ahead
The fully assembled cake keeps well, covered, at cool room temperature for up to 1 day. For longer storage, refrigerate it well covered for up to 4 days. Let chilled cake sit at room temperature for 30–45 minutes before serving so the frosting softens and the flavors open up.
You can bake the cake layers up to 2 days in advance. Once completely cool, wrap each layer tightly in plastic wrap and store at room temperature, or freeze for up to 2 months. Thaw frozen layers, still wrapped, at room temperature before frosting.
The butterscotch sauce can be made 1 week ahead and stored in an airtight container in the refrigerator; rewarm gently until pourable. The brown sugar buttercream can be made up to 3 days in advance; keep it refrigerated in an airtight container, then let it come to room temperature and re-whip briefly before frosting the cake.
Nutrition (per serving)
Approximate values for 1 slice (1/12 of the cake): about 650–700 calories, 36–40 g fat, 90–95 g carbohydrates, 75–80 g sugars, 5–6 g protein, and 450–550 mg sodium. These numbers will vary based on exact ingredient brands, portion sizes, and how much frosting, sauce, and toffee you use.
