Easy Last-Minute Coffee Cake

No eggs. No butter. No mixer. This coffee cake uses a full cup of mayonnaise as the fat AND the egg replacement, and it works shockingly well. Mayo is just oil, eggs, and acid already emulsified together, so it does triple duty in the batter.

The recipe is dead simple. Mix flour, sugar, cocoa powder, and baking soda in a bowl. Blend in cold coffee, mayo, and vanilla. Pour into a greased pan and bake. That’s it. No creaming, no alternating wet and dry, no separating eggs. The cold coffee intensifies the chocolate flavor without making the cake taste like coffee. It’s the same trick professional bakers use in chocolate layer cakes.

The texture is surprisingly moist and tender for a cake this easy. The mayo keeps the crumb soft, and the baking soda gives it a good rise despite having no eggs or butter in the traditional sense.

Pro Tips

• Use cold coffee, not hot. Hot liquid activates the baking soda too early and the cake falls flat.
• Grease AND flour the pan. This batter sticks without both.
• Test with a knife at 40 minutes. Ovens vary, and 45 minutes might be too long in a hotter oven.
• This cake is best served the same day. Without butter, it dries out faster than a traditional cake.

Variations

• Streusel top: Mix ¼ cup brown sugar, 2 tablespoons flour, and 2 tablespoons cold butter into crumbs. Sprinkle over the batter before baking for a crunchy top.
• Mocha glaze: Stir powdered sugar with a tablespoon of strong coffee for a quick drizzle.
• Without cocoa: Skip the cocoa for a plain vanilla coffee cake and increase flour by 2 tablespoons.