1/2 cup margarine
1/2 cup packed brown sugar
2 cups peanut butter
2 1/2 cups confectioners' sugar
2 cups semisweet chocolate chips (dairy free)
1. Melt margarine over low heat. Add sugars, peanut butter and vanilla. Mix well.
2. Press into a 9 x 13 inch pan.
3. Melt chocolate chips and spread over the top. Cool.
I found this on Allrecipes.com