Nutrition values are an estimate. Baked in a half sheet pan, 41 x 28.8 cm or 16 x 11.3 inches, greased and lined with parchment with an overhang. Let the butter and sugar mixture cool to warm before it meets the eggs, or they will scramble. Beat the eggs and vanilla until foamy for the shiny, crackly top. A toothpick should come out with moist crumbs, not clean.