Easy Chocolate Sheet Cake

Easy chocolate sheet cake is the Texas-born bake sale standard for good reason. One saucepan, no stand mixer, and a 9 by 13 pan that feeds a crowd. The batter comes together fast enough to slide into a hot oven before the coffee finishes brewing.

The trick is the boiled butter-cocoa start. Butter, water, oil, and cocoa powder go into a saucepan together and come to a full boil. That hot cocoa base blooms the flavor and gives the cake its trademark deep chocolate character. Separately, buttermilk and baking soda get combined early so the acid and base meet; the reaction is what makes the cake fluffy and tender. Off the heat, buttermilk mixture, eggs, vanilla, flour, sugar, and a teaspoon of cinnamon stir in for the hot chocolate-cinnamon note that sets this apart from plain chocolate cake.

The hot oven (400°F / 205°C) and short 15 to 20 minute bake keeps the cake moist and slightly fudgy in the middle. Frost right in the pan.

Kitchen Tips

• Mix the buttermilk and soda first and let it sit while other ingredients gather. This lets the acid start waking up the leavening.
• Bring the butter mixture to a true rolling boil before pulling it off the heat. A mild simmer won’t bloom the cocoa as effectively.
• Test early. At 400°F (205°C) this cake can go from perfect to overbaked in two minutes. Start checking at 15.
• Pour hot boiled frosting (the traditional pairing) over the cake while still warm so it soaks in slightly. A classic chocolate-pecan poured frosting is the match.

Variations

• Texas sheet cake finish: Top with a classic pecan poured chocolate frosting for the authentic Lone Star version.
• Coffee depth: Replace the water with hot brewed coffee for deeper chocolate notes.
• Mexican chocolate lean: Double the cinnamon and add a pinch of cayenne for a warmer, spiced cake.