1/2 cup butter or margarine
2 cups granulated sugar
1/2 cup evaporated milk
3 cups rolled oats
1/2 cup cocoa powder
1 cup chopped nuts (optional)
1 teaspoon vanilla extract

Combine oats, vanilla extract and nuts in a bowl and set aside.

Combine sugar, cocoa and evaporated milk in a heavy, 2-quart saucepan. Bring to a full rolling boil over medium high heat, stirring constantly. Let boil, while stirring, for 2 minutes.

Remove pan from heat and add the butter. Stir until butter is melted. Quickly add oat mixture to pan and stir until well mixed. Drop by the spoonful onto wax paper. Let cool for 2 hours to set.