1 1/2TbspmilkI use whipping cream but can also use buttermilk
1Tbspcocoa powder
1cuppowdered sugar
1/4tspvanilla
Instructions
Cake Batter
Mix together flour, sugar and salt in a small mixing bowl.
In a small sauce pan combine butter, cocoa and water. Stir until butter melts and mixture comes to a boil.
Pour mixture over dry ingredients and stir to combine.
Add in egg yolk, buttermilk, baking soda and vanilla. Stir to combine.
Pour mixture into a greased 9 x 7 inch baking pan.
Bake at 350 degrees for 15 minutes or until toothpick comes out clean.
Frosting
As soon as cake comes out of oven mix up frosting.
In a small sauce pan combine butter ,milk, cocoa powder, and powdered sugar.
Stir until butter melts and ingredients are combined. Frosting will be thin. Do not allow it to boil.
Add in vanilla.
Pour hot frosting over hot cake out of the oven.
Spread to cover cake.
Video
Notes
If you don't have a 9 x 7 inch baking pan use an 8 x 8 inch pan.
Don't overbake the sheet cake, it will dry out
Always frost the cake while it is still hot. The frosting will turn fudgy and delicious. Use a plastic disposable knife to cut the cake for a nice clean cut.