Génoise is the classic, plain butter sponge cake. Its open-grained texture makes it a perfect vehicle for moistening with liqueurs and filling with delicate, rich buttercreams.
Preheat oven to 350°. Prepare pans: Line bottoms of round or square pans with parchment or waxed paper. Line bottom of jelly-roll pan with parchment paper long enough to hang over at 2 opposite ends. Spray dome or bombe mold with pan release such as Pam.