1. Mix sugar, cocoa, butter/margarine, milk, vanilla, and peanut butter together in a saucepan and bring to a boil.
2. Boil for 1 minute while stirring to prevent burning.
3. Fold in oatmeal and stir until well mixed. All of the oatmeal should be mixed into the liquid.
4. Pour and press mixture into a greased 9x9 pan and refrigerate until solid.
5. Cut into squares or use a cookie cutter to make hearts, or other shapes.