Six Recipe

Prepare

Preheat the oven to 350°F (175°C). Grease and flour two 8-inch round cake pans (or line with parchment circles).

Dry ingredients

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

Cream butter and sugar

In a large bowl or stand mixer fitted with the paddle attachment, cream 3/4 cup softened unsalted butter and 1.5 cups granulated sugar on medium speed until light and fluffy, about 3–4 minutes. Scrape down the bowl as needed.

Add eggs and vanilla

Add the 3 large eggs, one at a time, mixing on low speed and scraping down the bowl after each addition. Mix in 2 tsp vanilla extract until incorporated.

Combine wet and dry

With the mixer on low, add one-third of the dry ingredients, then half of the 1 cup buttermilk, then another third of the dry ingredients, the remaining buttermilk, and finish with the last third of the dry ingredients. Mix just until combined — do not overmix.

Bake

Divide batter evenly between the prepared pans and smooth the tops. Bake in the preheated oven for 22–28 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs. Rotate pans halfway through baking for even browning.

Cool

Allow the cakes to cool in the pans for 10 minutes, then run a thin knife around the edges, invert onto a wire rack, remove parchment (if used), and let cool completely before frosting, about 1–1.5 hours.

While the cakes cool, make the syrup. In a small saucepan combine 1/4 cup water and 2 tbsp granulated sugar. Heat gently, stirring, until sugar dissolves. Remove from heat and stir in 1/2 tsp vanilla. Let cool. Brush the cooled syrup lightly over each cake layer to keep the cake moist (use about 1–2 tbs per layer).

Beat butter

In a clean bowl or stand mixer fitted with the paddle attachment, beat 1 cup softened unsalted butter on medium speed until creamy, about 2 minutes.

Add sugar and flavor

Gradually add 3.5 cups confectioners' sugar, about 1 cup at a time, mixing on low to incorporate between additions to avoid a powdered-sugar cloud. Add 1.5 tsp vanilla extract and 1/4 tsp fine sea salt.

Adjust texture

Add 2 tbsp heavy cream (or milk) and increase speed to medium-high; beat until the frosting is light and fluffy, about 2–3 minutes. If frosting is too stiff, add more cream 1 tsp at a time. If too thin, add more confectioners' sugar 1/4 cup at a time.

Level and layer

If the cake domes are uneven, level the tops with a serrated knife. Place one cake layer on a serving plate or cake board. Optionally brush with simple syrup. Spread about 3/4–1 cup buttercream evenly over the first layer.

Top layer & crumb coat

Place the second cake layer on top. Apply a thin crumb coat (a light layer of frosting to trap crumbs) over the top and sides of the cake using an offset spatula. Chill the cake in the refrigerator for 20–30 minutes to set the crumb coat.

Final coat and decorate

Apply the remaining buttercream in a smooth final layer. Use an offset spatula or bench scraper for clean edges. Decorate the top with fresh berries or edible flowers and sprinkle with sprinkles or toasted nuts as desired.

Serve

Let the assembled cake sit at room temperature for 20–30 minutes before slicing for the best texture. Store leftovers covered in the refrigerator for up to 4 days (bring to room temperature before serving).