Small-Batch Texas Sheet Cake

Lightly spray a quarter sheet pan with nonstick cooking spray and preheat your oven to 350 degrees.
In a large bowl whisk together flour, sugar, cocoa powder, salt, and baking soda and set it aside.
1 cup flour, 1/2 cup sugar, 3 TBS unsweetened cocoa powder, 1/8 tsp sea salt, 1/2 tsp baking soda
In a microwavable measuring cup, melt butter in the microwave in 30 second intervals until fully melted. Let cool slightly.
1/2 cup butter, melted
Whisk the egg, vanilla, buttermilk, and water into the melted butter until smooth.
1 egg, 1 tsp vanilla, 1/4 cup buttermilk, 1/2 cup water
Pour the wet ingredients into the dry ingredients and mix until an even cake batter forms.
Pour cake batter into the prepared quarter sheet pan.
Bake Texas sheet cake for for 15-16 minutes at 350 degrees, until a toothpick inserted in the center comes out clean.

While the cake is baking, in a medium saucepan, melt butter over medium heat.
6 TBS unsalted butter
Whisk in the cocoa powder, buttermilk, vanilla and salt and mix until smooth.
3 TBS cocoa powder, 3 TBS buttermilk, 1 tsp vanilla, 1/8 tsp sea salt
Remove frosting from heat and whisk in powdered sugar.
2 cups powdered sugar
If you're adding chopped nuts, fold them in.
When the cake comes out of the oven, immediately pour the frosting over cake and spread it around using a rubber spatula or the back of a large spoon.
Let the Texas sheet cake cool for at least 30 minutes prior to slicing into 12 pieces and serving.