These are super easy to make and the frosting is optional.
Brownies:
1 (19.5-19.8 oz) brownie mix
1/2 cup veg oil
1/4 cup water
4 eggs
1/3 cup creamy peanut butter
1/3 cup brown sugar
Frosting:
6 Tbl creamy peanut butter
1/4 cup (1/2 stick) unsalted butter, softened
2 cups powdered sugar
3-4 Tbl milk
Preheat oven to 350, spray bottom of a 13X9 baking pan. Combine brownie mix, oil, water, and 3 of the eggs in a medium bowl until just blended. Spread batter into the pan. Mix brown sugar, peanut butter and remaining egg in a small mixing bowl until blended. Drop by the tablespoon onto the brownie mixture. Use the tip of a knife to cut through the peanut butter to create marble effect. Bake for 32-35 minutes, until toothpick comes out clean. Cool completely. Spread frosting over cooled brownies. Cut into squares
For Frosting: Beat peanut butter and butter until blended. Gradually add the powdered sugar and milk until smooth. Beat until light and creamy.
Michele Tracey, Food Editor