1 cup sugar
1/2 c. cocoa (regular or dutch)
1/4 c. cornstarch
1/2 t. salt
2 1/2 c. milk (I use 1%)
2 T. butter
2 t. vanilla extract
In medium saucepan, whisk together the sugar, cocoa, cornstarch and salt. Slowly add, while whisking the milk.
Place over medium high heat and whisk constantly until mixture begins to boil. Remove from heat and immediately add the butter and vanilla extract. Stir until butter is melted and mixture is smooth. Pour into a large bowl and cover with clear plastic wrap directly on the surface to prevent a skin from forming while it cools. Refrigerate until set at least two hours.