YELLOW GENOISE CAKE

Steps:

• Preheat oven to 350 degrees. Butter a 12-by-18-inch standard jelly-roll pan, line with parchment paper, butter and flour the paper, and set aside.
• Set the metal bowl of an electric mixer over, but not in, a pot of simmering water. Combine sugar and eggs in the bowl, and whisk until mixture is warm to the touch, about 2 minutes.
• Transfer the bowl to an electric mixer fitted with the whisk attachment, and beat on high speed until mixture is very thick and pale, 6 to 8 minutes. With a rubber spatula, gently transfer mixture to a large clean mixing bowl. Sift in flour in three additions, folding gently after each. In a small bowl, combine butter and vanilla, then add in a steady stream as you fold in the third addition of flour. Fold gently, and pour out onto prepared pan. Smooth top with offset spatula.
• Bake until cake is springy to the touch and golden brown, 18 to 20 minutes. Remove from oven, and let cool on a wire rack. Wrap tightly with plastic wrap, and refrigerate for up to 3 days or freeze for up to 1 month. When ready to use, turn out cake onto a cutting board covered with a clean piece of parchment or wax paper, and peel the paper off the cake.