Minimalist Cake Recipe

Preheat oven to 325 degrees F or 160 degrees C. Lightly grease two 6-inch wide, 3-inch high cake pans. Line the bottoms with parchment paper. Set aside.

Mix fresh milk and vinegar in a large measuring jug and set aside for 5 minutes or until thickened slightly. Add eggs, oil, and vanilla flavoring. Gently whisk until mixed well. Set aside. 

In a large bowl, sift cake flour, cocoa powder, baking soda, and baking powder. Stir in sugar and salt into the flour mixture. Make a well. Pour the liquid ingredients into the well. 

Starting in the middle using a large spatula, start stirring the liquid ingredients from the center. (The flour mixture will slowly fall into and combine with the liquid ingredients.) Once mixed but still lumpy, switch to a large whisk and whisk until the mixture becomes smooth and transforms into a mixture that's pourable. Scrape the sides and bottom as necessary.   

Evenly divide the cake batter between the two prepared cake pans, about 420 grams each. Bake in the center of the preheated oven for about 40 minutes, rotating the pans halfway through the baking time. Use a toothpick or cake tester to test for doneness then remove from the oven and let cool completely on a wire rack. Set aside.    

Meanwhile, make the Swiss buttercream: In the bowl of a stand mixer, mix egg white, sugar, and salt. Place over a pot of gently simmering water, stirring constantly. Heat until 160 degrees F or 70 degrees C, or until the egg white has become hot to the touch and the sugar and salt granules have both dissolved. Remove from heat. 

Place the bowl in the stand mixer and using the whisk attachment, whisk on medium speed until the mixture has cooled down to room temperature and the bowl is no longer warm or is cool to the touch.

Once cool, start adding the softened butter, one tablespoon at a time, whisking until well blended after each addition. Whisk until smooth and fluffy. Add vanilla flavoring and whisk until mixed. 

To assemble the cake, remove parchment from each cake and level each cake layer by trimming the tops until even. Place a cake layer on a turntable. Add about 1 cup frosting on the cake and level the frosting on the top of the cake layer using an offset spatula, pushing the frosting just beyond the edges. Place the second cake on top. Add another 1 cup frosting on the cake and spread on top and the sides of the cake. Smooth the frosting on the top then smooth the frosting up the sides to create a small wall of frosting above the top. Chill the cake in the refrigerator for at least 1 hour.     

Meanwhile, to make the simple cake design, divide the leftover frosting into three small bowls. Add food coloring as desired to each and mix thoroughly. (To make the chocolate buttercream, mix 2 teaspoons cocoa powder, sifted, to about 1/4 cup buttercream.) 

Remove cake from the refrigerator. Place a small dollop of colored frosting on the cake. Using an offset spatula, smear the dollop. Repeat with another colored frosting. Repeat until desired design is made. Transfer a portion of your desired frosting for writing into a piping bag with the tip's end snipped off. (You can also use a small round piping tip.) Write your message, using the offset spatula as needed to correct mistakes. Slice and serve.