Instructions
1. Prepare the Cake
- Preheat oven to 350°F (175°C). Grease a 13×18-inch rimmed baking sheet.
- Whisk together flour, sugar, salt, baking soda, and cinnamon (if using).
- In a saucepan, melt butter, water, and cocoa powder over medium heat. Bring to a gentle boil, then remove from heat.
- Pour warm cocoa mixture into the dry ingredients; stir until combined.
- Whisk sour cream, eggs, and vanilla; add to batter and stir until smooth.
- Pour batter into prepared pan and spread evenly.
2. Bake the Cake
- Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean. Prepare the icing while the cake bakes.
3. Make the Icing
- Melt butter in a saucepan over medium heat. Add cocoa powder and milk; whisk until smooth. Bring to a gentle simmer, then remove from heat.
- Gradually whisk in powdered sugar until smooth. Stir in vanilla extract.
- Fold in nuts (optional).
4. Finish the Cake
- Immediately pour warm icing over the hot cake. Spread evenly with an offset spatula.
- Let cool completely before slicing and serving.
Cooking Notes
- Pour icing over the warm cake for a fudgy texture.
- Store leftovers in an airtight container at room temperature for up to 3 days, or refrigerate for up to 5 days.
Variations
- Cinnamon Twist: Add cinnamon to the batter for a spiced note.
- Buttermilk Substitute: Use buttermilk or a mixture of milk and lemon juice/vinegar.
- White Texas Sheet Cake: Omit cocoa; add almond extract to batter and icing.
Frequently Asked Questions (FAQs)
Can I make this ahead?
Yes! Store cooled cake in an airtight container at room temperature or in the refrigerator for up to 3-5 days.
How do I store leftovers?
Store in an airtight container at room temperature (up to 3 days) or refrigerate (up to 5 days).
Can I freeze it?
Yes! Wrap slices tightly and freeze for up to 2 months. Thaw overnight in the refrigerator.
What should I serve it with?
Vanilla ice cream, whipped cream, milk, or coffee are all delicious pairings.
Can I use a smaller pan?
A 13×18 inch pan is recommended. A smaller pan will result in a thicker cake; adjust baking time accordingly.

Texas Sheet Cake is a simple, crowd-pleasing dessert with rich chocolate flavor and a moist texture. Enjoy!