Chocolate pudding

Mmmmm, pudding.

3/4 cup sugar
1/3 cup cocoa powder
2 tablespoons cornstarch
2 2/3 cups milk
4 beaten egg yolks
1 tablespoon butter
1 1/2 teaspoons vanilla

In a heavy saucepan combine sugar, cocoa, and cornstarch. Add milk. Cook and stir over medium heat til mixture is thickened and bubbly. Cook and stir for 2 minutes more. Remove from heat. Gradually stir about 1 cup of the hot mixture into the beaten eggs. Return all of the egg mixture to the pan and bring to a gentle boil. Reduce heat. Cook and stir for 2 minutes more. Remove from heat. Stir in butter and vanilla. Pour pudding into a bowl and cover with plastic wrap. Do not stir! Chill.