Step 1

Preheat the oven to 350 degrees. Butter and flour two 8-inch cake pans

Step 3

Cream the butter and sugar on high speed until light and fluffy in the bowl of an electric mixer fitted with a paddle attachment. On medium speed, add the eggs, one at a time, then the sour cream, zests, and vanilla, scraping down the bowl as needed. Mix well. Sift together the flour, cornstarch, salt, and baking soda. On low speed, slowly add the flour mixture to the butter mixture and combine just until smooth.

Step 37

Pour the batter evenly into the pans, smooth the tops with a spatula, and bake in the center of the oven for 40 to 45 minutes, until a toothpick comes out clean. Let cool in the pans for 30 minutes, then remove to wire racks and let cool to room temperature.

Step 71

To make the filling for one cake, whip the cream by hand or in a mixer until firm; add the sugar and vanilla. Slice one of the cakes in half with a long, sharp knife. Place the bottom slice of the cake on a serving platter, spread with half of the whipped cream, and scatter with sliced strawberries. Cover with the top slice of the cake and spread with the remaining cream. Decorate with strawberries.