1 box chocolate Pillsbury cake mix
1/2 c. butter
1 lg. pkg. chocolate chips
1 c. sour cream
1 egg

Preheat oven to 350 degrees. Mix cake mix and butter until crumbly. Press all but 2/3 cup of mixture into ungreased 13 x 9-inch pan. Pour chocolate chips over this crust. Mix sour cream and egg by hand with a fork. Drizzle this over chips and cover evenly. Take remaining 2/3 cup of cake batter; add 1 tablespoon white sugar and sprinkle over sour cream sauce. Bake at 350 degrees for 25 to 30 minutes, or until bubbly. Cut when cool and refrigerate (because of sour cream).