This is really easy. Also known as saucepan brownies.
You will need:
4 squares of unsweetened chocolate
1 cup butter
2 cups granulated sugar
3 eggs, beaten
2 tsp vanilla
1 cup all purpose flour
1 cup chopped walnuts or pecans
Mix butter and chocolate in pan and melt. Remove from heat and let
cool. Add sugar, eggs, and vanilla extract. Mix. Add flour.
Pour into greased & floured 9″ square baking pan.
Bake 50 minutes in pre heated oven at 350 degrees. Cool completely before cutting.