1/2 cup butter (or margarine, whatever you have)
1/2 cup packed brown sugar (light or dark, again whatever you have)
1 teaspoon vanilla extract
2 cups peanut butter
2- 1/2 cups confectioners sugar
2 cups semisweet chocolate chips
Place all ingredients except the chocolate chips in a large microwave safe bowl. Microwave until butter and peanut butter are melted, one to two minutes (time will vary by microwave).
Remove from microwave and use a large spoon to stir all of the ingredients together until they form a ball of dough that leaves the side of the bowl. Pat into a 9x13 pan.
Pour chocolate chips into another microwave safe bowl and microwave at 30 second intervals, stirring after each, until completely melted. Spoon over top of peanut butter mixture and spread evenly.
Allow to cool completely at room temperature until chocolate hardens again or place in the refrigerator for faster hardening. Cut into squares and serve