2 2/3 c. powdered sugar
2 c. peanut butter
3/4 c. brown sugar
1 tsp. vanilla
1 c. butter, melted and divided
12 oz. chocolate chips

Mix together both sugars, peanut butter, vanilla and 1/2 cup of the melted butter. Press into a greased 9 x 13-inch pan.

Melt chocolate chips with the remaining 1/2 cup of butter. Pour over top of peanut butter mixture. Chill. Cut into bars.