Quick Recipe Version (TL;DR)

Yield: 12 servings
Prep Time: 1 hour
Cook Time: 55 minutes
Total Time: 3 hours 30 minutes (includes cooling/chilling)

Quick Ingredients

Cake (3 layers, 8-inch): 3 cups (360 g) cake flour, 2 1/2 tsp baking powder, 1/2 tsp baking soda, 3/4 tsp salt, 1 cup (226 g) unsalted butter, 2 cups (400 g) sugar, 3 tbsp lemon zest, 1/4 cup (60 ml) neutral oil, 4 large eggs, 1/2 cup (120 ml) lemon juice, 1 cup (240 ml) buttermilk, 2 tsp vanilla
Lemon Curd (filling): 4 large yolks + 1 whole egg, 3/4 cup (150 g) sugar, 1 tbsp zest, 1/2 cup (120 ml) lemon juice, 6 tbsp (85 g) butter, pinch salt
Lemon Buttercream: 1 1/2 cups (340 g) butter, 5 cups (600 g) powdered sugar, 1 tbsp zest, 3–4 tbsp lemon juice, 2–4 tbsp heavy cream, 1 tsp vanilla, 1/4 tsp salt
Optional Candied Lemons: 2 lemons, 1 cup (200 g) sugar, 1 cup (240 ml) water

Do This

1. Make curd: Whisk yolks, egg, sugar, zest, and juice; cook to 170–175°F until thick. Strain, whisk in butter, cover, chill 1 hour.
2. Heat oven to 350°F (177°C). Grease and line three 8-inch pans.
3. Cake batter: Cream butter, sugar, and zest; beat in oil and eggs. Alternate dry ingredients with buttermilk + lemon juice + vanilla. Divide into pans.
4. Bake 24–28 minutes; cool 10 minutes, then turn out and cool completely.
5. Optional: Simmer lemon slices in sugar-water 15–20 minutes; dry on rack.
6. Buttercream: Beat butter fluffy; add powdered sugar, zest, salt; beat in lemon juice and cream to silky.
7. Assemble: Level cakes. Pipe buttercream dam; fill with curd (2 layers). Crumb coat, chill, final frost, garnish, slice.

Why You’ll Love This Recipe

Bright, natural lemon flavor from generous zest and fresh juice in every layer.
Luscious textures: tender cake crumb, silky lemon curd, and pillowy buttercream.
Elegant presentation with optional candied lemon slices that sparkle.
Make-ahead friendly components for low-stress assembly.

Grocery List

Produce: 6–7 large lemons (you’ll need 5–6 tbsp zest and about 1 cup juice total)
Dairy: Unsalted butter (about 680 g/6 sticks total), buttermilk (1 cup), heavy cream (1/4 cup), large eggs (9 total: 4 for cake, 1 for curd, 4 yolks for curd)
Pantry: Cake flour, granulated sugar, powdered sugar, baking powder, baking soda, fine sea salt, vanilla extract, neutral oil (canola or light olive)

Full Ingredients

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

3 cups (360 g) cake flour
2 1/2 tsp baking powder
1/2 tsp baking soda
3/4 tsp fine sea salt
1 cup (226 g) unsalted butter, room temperature
2 cups (400 g) granulated sugar
3 tbsp finely grated lemon zest (from 3–4 lemons)
1/4 cup (60 ml) neutral oil (canola or light olive)
4 large eggs, room temperature
1/2 cup (120 ml) fresh lemon juice, room temperature
1 cup (240 ml) buttermilk, room temperature
2 tsp pure vanilla extract

For the Lemon Curd Filling

4 large egg yolks
1 large egg
3/4 cup (150 g) granulated sugar
1 tbsp finely grated lemon zest
1/2 cup (120 ml) fresh lemon juice
6 tbsp (85 g) unsalted butter, cut into pieces
Pinch fine sea salt

For the Lemon Buttercream

1 1/2 cups (340 g) unsalted butter, room temperature
5 cups (600 g) confectioners’ sugar, sifted
1 tbsp finely grated lemon zest
3–4 tbsp fresh lemon juice, to taste
2–4 tbsp heavy cream, as needed
1 tsp pure vanilla extract
1/4 tsp fine sea salt

Optional Garnish: Candied Lemon Slices

2 medium lemons, very thinly sliced (seeds removed)
1 cup (200 g) granulated sugar
1 cup (240 ml) water
2–3 tbsp extra sugar for dusting (optional)

Step-by-Step Instructions

Step 1: Make the lemon curd (do this first)

In a medium saucepan off heat, whisk together the 4 yolks, 1 whole egg, sugar, lemon zest, and a pinch of salt until smooth. Whisk in the lemon juice. Set over medium-low heat and cook, stirring constantly with a heatproof spatula, until thickened and just beginning to bubble, 6–10 minutes, or until it reaches 170–175°F and coats the back of a spoon.

Immediately strain through a fine-mesh sieve into a bowl. Whisk in the butter pieces until glossy. Press plastic wrap directly onto the surface and chill until cold and spreadable, at least 1 hour.

Step 2: Prep pans and preheat

Heat the oven to 350°F (177°C). Grease three 8-inch round cake pans, line the bottoms with parchment rounds, and lightly flour the sides (or use baking spray with flour). If you have cake strips, soak and wrap them around the pans for flatter layers.

Step 3: Mix the cake batter

In a medium bowl, whisk together cake flour, baking powder, baking soda, and salt. In a large bowl, rub the lemon zest into the sugar with your fingertips until fragrant. Add the butter and beat on medium-high until pale and fluffy, 3–4 minutes. Beat in the oil. Add the eggs one at a time, beating well and scraping the bowl after each.

In a measuring cup, stir together the lemon juice, buttermilk, and vanilla. With the mixer on low, add the dry ingredients in 3 additions alternating with the lemon-buttermilk mixture in 2 additions, beginning and ending with dry. Mix just until combined; the batter should be smooth and velvety.

Step 4: Bake and cool the layers

Divide the batter evenly among the prepared pans (about 520–560 g per pan). Smooth the tops and tap gently to release large air bubbles. Bake 24–28 minutes, until the tops spring back, a toothpick comes out clean, and the edges are just pulling from the sides.

Cool on a rack 10 minutes, then run a thin knife around the edges and turn out onto racks. Peel off parchment and cool completely, 45–60 minutes.

Step 5: Candy the lemon slices (optional)

In a wide skillet, bring sugar and water to a gentle simmer over medium heat, stirring just to dissolve. Add the lemon slices in a single layer. Simmer very gently (no vigorous boiling) until the rinds turn translucent, 15–20 minutes. Lift slices to a rack with tongs and let dry until tacky, 45–60 minutes. Dust with a little sugar if you like.

Step 6: Make the lemon buttercream

Beat the butter on medium-high until creamy and pale, 2 minutes. Add the sifted confectioners’ sugar gradually on low. Add lemon zest and salt, then lemon juice and enough cream to reach a silky, spreadable consistency. Beat on medium-high 2–3 minutes until light and fluffy. If too soft, chill 10 minutes; if too stiff, add a teaspoon of cream at a time.

Step 7: Level, fill, and stack

Use a serrated knife to level any domed cake tops. Place the first layer on a board. Spread a thin smear of buttercream on top. Pipe a 1/2-inch tall buttercream “dam” around the edge and spoon in half the lemon curd. Top with the second layer and repeat with dam + remaining curd. Place the third layer on top and press gently so the filling reaches the edges without spilling.

Step 8: Crumb coat, chill, finish, and garnish

Apply a thin crumb coat of buttercream over the entire cake and chill 15–20 minutes. Add a final, thicker coat and smooth with an offset spatula or scraper. Create swoops if you like. Garnish with candied lemon slices and a sprinkle of fresh zest. Let the cake sit 20 minutes at room temperature before slicing for the cleanest cuts.

Pro Tips

For maximum lemon flavor, rub zest into the sugar before creaming—this releases fragrant oils.
Weigh your flour for accuracy; too much flour makes cake dry. If using cups, spoon and level.
Room-temperature ingredients blend smoothly and help prevent curdled batter.
Pipe a buttercream dam so the curd stays neatly between layers.
Use an oven thermometer and start checking cakes at 22 minutes to avoid overbaking.

Variations

Lemon-Blueberry: Fold 1 1/2 cups fresh blueberries (tossed with 1 tbsp flour) into the batter. Garnish with extra berries and lemon zest.
Meyer Lemon: Swap regular lemons for Meyer lemons for a sweeter, floral note; reduce sugar in the curd by 1–2 tbsp if desired.
Cupcakes: Makes about 24. Bake 18–20 minutes. Core and fill each cupcake with a spoonful of lemon curd, then frost.

Storage & Make-Ahead

Curd can be made up to 1 week ahead; keep refrigerated with plastic wrap pressed to the surface. Cake layers can be baked, cooled, wrapped tightly, and refrigerated up to 2 days or frozen up to 2 months (thaw in the fridge). Buttercream keeps 1 week refrigerated or 2 months frozen; bring to room temp and rewhip before using. Assembled cake holds 3 days refrigerated; bring to room temperature 45–60 minutes before serving. Candied lemon slices keep 3–4 days airtight at room temperature.

Nutrition (per serving)

Approximate per slice (1/12 of cake): 760–840 calories; 35–40 g fat; 13–17 g saturated fat; 105–115 g carbohydrates; 1–2 g fiber; 75–85 g sugars; 6–8 g protein; 260–340 mg sodium. Values will vary based on exact ingredients and garnish.

Lemon Layer Cake With Lemon Buttercream