Here is one that I learned from my grandmother years ago.

Chocolate Gravy

3 cups milk
1.5 cups sugar
6 tablespoons cocoa (more or less, according to taste)
4 tablespoons flour
Dash of salt
2 tablespoons butter
1 tablespoon vanilla

Combine all dry ingredients and set aside. Heat the milk in a medium saucepan until just about boiling. Slowly add the dry ingredient mixture, stirring constantly, and bring to a boil. Reduce heat, and cook until desired thickness is reached. Remove from heat, and stir in the butter and vanilla. Allow to cool five minutes (the mixture will thicken) and serve with biscuits.