This Texas Sheet Cake Recipe is the best! Baked in a half sheet pan, it feeds a crowd and is perfect for a potluck! A large thin cake, slightly chewy and a little dense with a warm gooey chocolate frosting poured over the warm cake!
In a mixing bowl combine flour, sugar, brown sugar and salt.
In a medium saucepan, melt butter then add cocoa powder, stirring together until mixed. Add boiling water and allow mixture to boil for 30 seconds, then remove from heat.
Pour over flour mixture, mixing lightly to cool.
In a 1 cup measuring cup, pour in buttermilk, beaten eggs, baking soda and vanilla. Stir to combine. Pour into butter/cocoa/flour mixture, whisking until just combined and only a few lumps remain.
Pour into sprayed half sheet pan (13 x 18") and bake at 350° F for 20-25 minutes until it springs back lightly when touched. See notes for baking in different sized pans. Remove from oven and cool 5 minutes before pouring on frosting.
Frosting
About 10 minutes into baking time, start making the frosting.
Using the same saucepan you made the cake batter in, melt butter over medium-low heat. Stir in cocoa powder to combine, remove from heat. Add powdered sugar, vanilla and milk stirring together until combined, then whisk until smooth.
If desired, add pecans to the frosting directly, mixing to combine or sprinkle over the top of cake after frosting.
Remove cake from oven and allow to cool 5 minutes on cooling rack, whisk frosting one more time, adding a bit of milk if it's too thick, it should be pourable and still warm. Pour warm frosting over warm cake, spreading with spatula until covered.
Serve warm or room temperature with or without a scoop of vanilla or chocolate ice cream.
Store leftover cake in airtight container or covered with plastic wrap for up to 3 days. May be refrigerated up to 7 days.
Video
Notes
*Buttermilk Substitutes | Mix one tablespoon white vinegar or lemon juice into a scant 1 cup milk, stir and allow to sit for 5-10 minutes before using. You may also substitute sour cream for buttermilk, or even try plain Greek yogurt.No half sheet pan? Cake may be baked in a 13x9" or 10x15" jelly roll pan. They will need to bake longer about 23-30 minutes until top springs back when lightly touched or when toothpick inserted comes out with a few crumbs. Do not overbake! Be careful with the jelly roll pan as you might overflow, if edges start to brown too quickly, cover lightly with sprayed foil.Notes about high altitude bakingCakes can be finicky at normal altitudes, but the higher the altitude the more testy they become, here are my tips for high altitude baking, sometimes you need to try a few times to figure out the best for your oven.
Decrease the double-acting baking powder or baking soda by one-quarter to one-half teaspoon for every teaspoon called for in the recipe, and add an extra egg, do not overbeat the eggs.
Decrease the sugar two to three tablespoons for each cup in the recipe.
Increase the liquid by three to four tablespoons for each cup liquid indicated.
Increase the flour by one to two tablespoons for each cup called for. Increase the baking temperature about 25 degrees.
Be sure to grease your pan extremely well and only fill ½ full as cakes like to stick more at altitude and will tend to rise quicker.