1/2 cup butter (room temperature) 2/3 cup white granulated 2ugar 1/2 packed brown sugar 2 tbsp milk 2 eggs 1/4 tsp salt 1/2 tsp baking powder 3/4 cup all purpose flour 1/3 cup unsweetened cocoa 1/2 cup semi sweet chocolate chips 1/4 cup peanut butter 1/3 cup peanut butter chips
In a large mixing bowl, cream together the butter and sugars.
Blend in eggs and milk.
Blend in salt and baking powder.
Stir in flour.
Divide the batter into two portions.
In one portion stir in cocoa and chocolate chips.
In the other portion stir in peanut butter and peanut butter chips.
Prepare an 8x10", 8x8" or 9x9" baking dish by greasing it or by lining it with aluminum foil and lightly greasing the foil.
Drop spoonfuls of the chocolate batter in the pan in a checkerboard pattern, dropping 7-8 spoonfuls, leaving gaps in between spoonfuls.
Fill in the spaces with the peanut butter batter, you should end up with a peanut/chocolate checkerboard pattern, more or less.
Swirl a butter knife through the batter 2-3 times in different directions and spread the batter evenly in pan.
Bake at 350F for 25-30 minutes until a toothpick inserted in the center comes out clean or with just a few moist crumbs (keep in mind that if you hit a chocolate chip you will see that).