Prepare sponge cake recipe and bake in either two 9" round baking tins or three 8" round baking tins greased on the bottoms only and lined with parchment or wax paper.
Cool cakes for 10 minutes in the pan, then invert, remove paper and turn right side up to cool completely on racks.
Meanwhile, prepare lemon curd and chill.
Combine whipping cream, sugar and vanilla in a chilled, deep bowl. Beat on high speed until peaks form.
Fold about 1 cup whipped cream into lemon curd to lighten, then fold in lemon curd into whipped cream just until combined.
Use whipped lemon frosting to fill and cover cake layers.
Makes 8 to 12 servings