Cake Slice Recipe

Prepare

Preheat oven to 350°F (175°C). Grease a 9-inch round cake pan and line the bottom with parchment; grease parchment as well, or use a 9x13 pan for sheet cake (adjust bake time as noted).

Dry ingredients

In a medium bowl, whisk together 2 cups all-purpose flour, 2 tsp baking powder, and 1/2 tsp fine salt until evenly combined.

Cream butter and sugar

In a large bowl or stand mixer fitted with the paddle attachment, beat 1/2 cup softened unsalted butter and 1 1/2 cups granulated sugar on medium speed until light and fluffy, about 3–4 minutes.

Add eggs and vanilla

Add 3 large eggs one at a time, mixing on low speed after each addition until incorporated. Scrape the bowl, then mix in 2 tsp vanilla extract.

Combine wet and dry

With the mixer on low, add the dry ingredients in three additions alternating with the 3/4 cup whole milk (start and end with dry). Mix just until combined after each addition to avoid overworking the batter.

Bake

Pour batter into the prepared pan and smooth the top. Bake at 350°F (175°C) for 25–30 minutes for a 9-inch round (35–40 minutes for a 9x13) or until a toothpick inserted into the center comes out with a few moist crumbs. Rotate pan halfway through baking for even color.

Cool

Let the cake cool in the pan on a wire rack for 10–15 minutes, then run a knife around the edge and invert onto the rack to remove parchment. Cool completely before slicing and frosting (about 1–2 hours).

Combine 1/4 cup water and 2 tbsp granulated sugar in a small saucepan. Warm over medium heat, stirring until the sugar dissolves. Remove from heat and stir in 1/2 tsp vanilla. Allow to cool slightly, then brush lightly onto the cake layers before frosting to add moisture and flavor.

Beat butter

In a large bowl or stand mixer, beat 1 cup softened unsalted butter on medium speed until creamy, about 1–2 minutes.

Add sugar and liquids

Gradually add 3 1/2 cups powdered sugar, about 1 cup at a time, beating on low to combine. Add 3 tbsp heavy cream, 1 tsp vanilla extract and 1/4 tsp fine salt. Once all sugar is added, increase speed to medium-high and beat until light and fluffy, 2–3 minutes. Adjust consistency with extra cream (1 tsp at a time) if too stiff or a little powdered sugar if too thin.

Frost the cake

If the cake has domed, level with a serrated knife. If using simple syrup, brush the cooled cake layers lightly. Place the bottom layer on a serving plate, spread a thin layer of buttercream, then top with the second layer (if split). Apply a crumb coat (thin layer of frosting) and chill 15 minutes to set. Finish with a final thicker layer of frosting, smoothing with an offset spatula or creating decorative swirls.

Garnish with 1/2 cup fresh berries or sprinkles as desired and dust lightly with 1 tsp powdered sugar. Slice into 10 standard cake slices (serving size ~1 slice) using a sharp knife wiped between cuts for clean edges.