4-Ingredient Oil Sponge Cake! Beginner-friendly step-by-step recipe for making a light 4-ingredient oil sponge cake, a super easy recipe that uses basic pantry ingredients. You just need 4 ingredients, eggs, flour, sugar, and oil. ABOUT The Recipe This 4-ingredient oil sponge cake is a variation of the classic European sponge cake called Genoise. Genoise is…