How to Make It
Preheat the oven to 350°. Butter and flour an 8-inch round cake pan. In a medium bowl, sift the flour with the cornstarch, baking soda and salt.
In a large bowl, using a handheld mixer, beat the butter until creamy. Add the 3/4 cup of sugar and beat at medium speed until light and fluffy. Add the eggs, 1 at a time, beating until incorporated. Add the sour cream, the orange and lemon zests and 1/2 teaspoon of the vanilla and beat until blended. Add the dry ingredients and beat at low speed until smooth.
Scrape the batter into the prepared pan and bake for about 40 minutes, or until golden and a skewer inserted in the center comes out clean. Transfer the pan to a wire rack and let the cake cool for 15 minutes before turning it out onto the rack to cool completely.
Beat the cream with the remaining 3 tablespoons of sugar and 1/2 teaspoon of vanilla until soft peaks form.
Slice the cake in half horizontally. Spread most of the whipped cream over the cut side of the bottom cake half. Layer most of the sliced strawberries on top. Replace the top half of the cake and garnish with the remaining whipped cream and strawberries. make ahead The cake can be frozen for up to 1 month. Let it cool completely before wrapping in plastic and then foil. The assembled cake can be prepared up to 2 hours ahead.