This Brown Butter Layer Cake with Chocolate Buttercream Frosting is rich and buttery but not overly sweet. It’s perfect for all seasons, really, with classic cake ingredients available year-round, butter, sugar, eggs, and flour.
The brown butter adds subtle depth to the cake, and the chocolate buttercream is heavenly. You don’t need to decorate further than the frosting but I added homemade macaroons filled with chocolate ganache as a finishing touch to an already beautiful cake.
Ingredients for the cake include; 3 sticks unsalted butter (12 ounces), plus more for greasing the pans, 2-1/4 cups all-purpose flour, plus more for dusting, 2-1/4 teaspoons baking powder, 1 teaspoon salt, 1-2/3 cups sugar, 1 vanilla bean, split and seeds scraped, 3 large egg yolks, 2 large eggs, 1-1/4 cups milk, at room temperature.
1. Preheat the oven to 325. Butter two 9-inch cake pans and line the bottoms with parchment paper. Butter the paper and dust the pans with flour, tapping out excess.
2. Melt the 3 sticks of butter in a medium saucepan. Cook over low heat, stirring occasionally. Butter will start to get foamy, about 5 minutes. Continue to cook and stir frequently, until milk solids turn brown and butter smells nutty. You will see browned bits on the sides and bottom of pan. Scrape the melted butter and bits into a large heatproof bowl. Set the bowl in an ice water bath until the butter begins to set around the edge, about 8 minutes.
3. In a medium bowl, whisk the 2-1/4 cups flour with the baking powder and salt. Set aside.
4. Remove the bowl containing brown butter from the ice bath. Transfer the butter to the bowl of a standing mixer fitted with a paddle attachment and beat until creamy.
5. To the mixer bowl, add the sugar and vanilla seeds and beat a medium-high speed until fluffy, about 3 minutes. Beat in the egg yolks followed by the whole eggs. Beat in the dry ingredients and milk in 3 alternating additions, scraping down the sides and bottom of bowl if necessary.
6. Pour the cake batter into the prepared pans and bake in the center of the oven for about 40 minutes, rotating the pans halfway through baking, until a toothpick inserted in the centers come out clean and cakes are golden.
7. Cool the cakes in the pans for 20 minutes, then invert them onto a rack to cool completely. Remove parchment paper.
Ingredients for the rich chocolate buttercream include; 1 cup sugar, 3 large egg whites, 1/4 teaspoon salt, 2 sticks plus 2 tablespoons unsalted butter (9 ounces), cut into tablespoons, at room temperature, 4 ounces extra-bittersweet chocolate, melted and cooled.
1. In a blender or food processor, pulse the sugar until powdery. Transfer the sugar to a medium heatproof bowl and whisk in egg whites and salt. Place the bowl over a saucepan of simmering water and whisk mixture gently until sugar is completely dissolved.
2. Transfer the warm egg-white mixture to the bowl of a standing mixer fitted with a whisk attachment. Add the vanilla and beat beat at medium-high speed until stiff and glossy, about 8 minutes.
3. Beat in the butter a few tablespoons at a time. Make sure pieces are fully incorporated before adding more. The buttercream should be light and fluffy. If it appears runny, place bowl in freezer for 5 to 10 minutes. Resume mixing.
4. Beat in the melted chocolate until fully incorporated into the buttercream. Remove bowl from mixer and beat mixture with wooden spoon to remove any air bubbles.
Directions for frosting the cake:
1. Carefully set one cake layer on a platter or cake stand. Spread the buttercream on top and cover with second cake layer.
2. Frost a thin layer of buttercream all over the layered cake. Refrigerate until set, about 5 to 10 minutes. This initial coat contains loose and stray crumbs and allows for a more finished looking cake.
3. Frost the cake with the remaining buttercream. Refrigerate until the frosting is firm, at least 15 minutes. Serve and enjoy!