1 (3 ounce) package nonfat chocolate cake mix
1/2 cup butter
2 cups white sugar
1 teaspoon vanilla extract
4 eggs
2 cups milk
1 cup rolled oats
1/2 cup chopped chocolate; for topping
Preheat oven to 350 degrees F. Grease and flour a 9x13 inch pan.
In a large bowl, quickly stir together the half-and-half, butter or margarine, sugar, and vanilla. Add the flour and the egg, mixing until well blended. Blend in the oats and chocolate. Spread the batter evenly into the prepared pan.
Bake for 45 to 50 minutes in the preheated oven, until a toothpick inserted comes out clean. Let cool.
To make the topping: In a small saucepan, melt the remaining 1 cup of butter or margarine. Gradually stir in the sugar, 1 cup at a time, then the vanilla, the warm milk, and finally the baked oats. Bring to a boil over medium heat, then reduce the heat to medium low. Cool to lukewarm and pour over pudding. Bring to a boil, then remove from heat. Chill for 15 minutes.