2/3 c. butter
1 (12 oz.) pkg. chocolate chips (divided), mini
1 1/2 c. sugar
1 1/2 c. flour
1 tsp. baking powder
1/2 tsp. salt
4 eggs
1 tsp. vanilla
1/2 c. chopped nuts

FROSTING:

2 c. whipping cream, whipped
1/4 c. powdered sugar
1 tsp. vanilla
2/3 c. mini chocolate chips

Line jelly roll pan (15 1/2 x 10 1/2 x 1 inch) with waxed paper; grease. Heat butter with 1 cup chocolate chips over medium heat until chocolate is melted. Stir in remaining ingredients except frosting. Spread evenly in pan. Bake 20- 25 minutes. Cool 10 minutes. Invert on board. Remove waxed paper and cool completely. Cut cake into 4 equal parts.

Place 1 piece on plate and spread with 3/4 cup of frosting. Repeat for all sections. Frost sides and top. Garnish with remaining chips.