Step 1

Preheat the oven to 350°F. Line the bottom of three 6-inch round cake pans or two 8-inch round cake pans with parchment paper rounds. Spray the parchment paper and sides of the pan with cooking spray. (All of this is essential to prevent cake from sticking!)

Step 2

Mix the dry ingredients: In a separate large bowl, whisk together the flour, baking powder, baking soda and salt and set aside.

Step 3

Mix the wet ingredients: In the bowl of an electric mixer, add the butter and sugar and cream together on high speed for 1 to 2 minutes or until mixture becomes pale light yellow in color. (Feel free to use a hand mixer for this if that is your preference.) Using a spatula, scrape the bowl down, then add in the eggs, one at a time, beating for 1 minute between each egg addition. Finally add the egg yolks, vanilla and yogurt and mix again on medium speed until well combined, about 1 minute longer. (NOTE: Do not add in the buttermilk yet.)

Step 4

With the mixer on low speed, add half of the dry ingredient mixture to the wet ingredients, then all of the buttermilk, followed by the remaining dry ingredients. Mix on medium low speed until just combined. (Alternating the flour and buttermilk will create a beautiful crumb for the cake!)

Step 5

Bake the cake: Divide the batter evenly between the prepared pans and smooth the tops. Bake for 25 to 35 minutes in the 8-inch pans or 30 to 40 minutes in the 6-inch pans, until a tester inserted into the center comes out mostly clean with just a few crumbs attached.

Step 6

Cool the cakes completely before removing them from the pan. To do so, run a butter knife around the edges of the pan, then invert them and place them on a wire rack. You can also make them up to a day ahead, then wrap tightly with plastic wrap and store at room temperature or in the fridge.

Step 7

Make the frosting: use my Dad's famous Chocolate Buttercream Frosting recipe for this cake.

Step 8

Frost the cake: Spread about 2 tablespoons of the frosting in the middle of a cake stand or platter (this will help anchor the cake). Invert the first layer of the cake onto the stand so the flat side of the cake is up. Top with about ½ cup of frosting. Using an offset spatula, spread the frosting to the edge of the cake, ensuring you have an even layer. Place the next layer of cake, flat-side up, on top of the first layer, and repeat, topping with an additional ½ cup of frosting and spreading it to the edge. Place the third layer (if using) flat-side up on top, then frost the top and sides of the cake with ½ to ¾ cup of frosting, using a bench scraper to create a uniform, very thin layer of frosting around the cake. It helps to do this while slowly spinning the cake stand, and gently pressing the scraper against the side of the cake. (This step is called a crumb coat which will allow for a beautiful, seamless look once complete.) Transfer the cake to the fridge for at least 15 minutes, or until the crumb coat layer of frosting has firmed up to the touch. Once the cake is chilled, repeat the process of frosting the top and sides of the cake with the remaining frosting, using an offset spatula. (Since the cake has been chilled, the crumb coat should allow for a smoother finish.)

Step 9

Enjoy immediately or store the cake in the fridge for up to 5 days, well-covered to ensure freshness.