15 graham crackers (2 1/2 x 2 1/2 inch)
1 c. firmly packed brown sugar
1 stick butter (no substitute)
1 stick butter
12 oz. semi sweet chocolate chips

Heat oven to 400 degrees. Line 13 x 9 inch pan with foil; grease foil with butter. Arrange graham crackers in prepared pan. (Some graham crackers may need to be broken apart so that the entire bottom is covered). In medium saucepan, combine brown sugar, butter and butter; bring to boil. Remove from heat; pour over graham crackers. Bake at 400 degrees for 5 minutes. Remove from oven; immediately sprinkle with chocolate chips. When chips are soft, spread over top. Chill about 30 minutes until chocolate is set. Cut into bars or break into pieces. Store in refrigerator.