In medium bowl, mix the graham cracker crumbs and oatmeal; set aside. In a large saucepan stir in the sugar, cocoa, milk, and margarine over medium heat until it is dissolved.
Bring the mix to a boil for two minutes-this is important. Remove from heat, and stir in the peanut butter and vanilla until it is well mixed. Blend in the oatmeal mixture-quickly. Beat by hand until it is thickened (only a few minutes), if necessary.
By teaspoon, drop onto waxed paper. Refrigerate or store in another cool place until firm.