Preparation

1. Preheat oven to 350°F. Butter and flour two 9-inch pans. Cut a circle of wax paper or parchment paper to fit the bottom inside of the pan. Place the circle inside the pan and butter and flour it as well.
2. Sift the flour, baking powder, and salt together in a mixing bowl and reserve.
3. Place the butter in the Cuisinart™ mixing bowl. Insert the flat mixing paddle. Turn to speed 2 to cream the butter, about 30 seconds. Add the sugar with the stand mixer running on speed 2. Mix until the sugar and butter are well creamed and light, about 2 minutes. Scrape the bowl and paddle and mix again for another 30 seconds. With the stand mixer running on speed 1, add the eggs and yolks, one at a time, making sure each is incorporated before adding the next. Mix in the vanilla. Scrape the bowl and paddle. With the stand mixer running on speed 1, add the dry ingredients and buttermilk alternately, beginning and ending with the dry ingredients. Increase to speed 2 and run for about 20 seconds. Scrape the bowl completely to make sure all ingredients are evenly incorporated.
4. Pour batter evenly into prepared pans. Bake in preheated 350°F oven for 30 to 35 minutes. The cakes should be slightly puffed and golden and a cake tester should come out clean.
5. Allow to cool on a wire rack. Once cool to the touch, release cakes from pan and continue to cool completely on the wire rack before frosting.