For a 12 by 16 in. sheet pan:

Beat together:

3 eggs
1 lb. brown sugar
1 tsp. vanilla

Add 5 1/4 oz. melted butter

Sift together and add:

2 cups all purpose flour
2 tsp. baking powder
1/2 tsp. salt

Add:

12 oz. choc. chips
1 cup large walnuts

Bake at 350 for 25 minutes or longer.
Cut into squares and serve.