Make Ahead Tip: Wrap cooled sponge cake layers airtight and refrigerate for up to 5 days or freeze for up to 3 months. Defrost at room temperature. Frost cake up to 2 hours ahead. Top with berries before serving.
Equipment: Two 9-inch round cake pans, parchment paper
To bring eggs to room temperature, either set them out on the counter for 15 minutes or submerge them (in the shell) in a bowl of lukewarm (not hot) water for 5 minutes; the eggs will beat to a greater volume.