Peanut Butter Cookie Dough Brownies

(Courtesy of thenonpareilbaker.blogspot.com)

Ingredients:
1 box brownies (9x13 pan size), baked according to package directions and cooled
1/4 c. salted butter, softened
1/2 c. peanut butter
1/2 c. granulated sugar
1 c. brown sugar
1/4 c. plus 2 Tbsp. milk
1 Tbsp. vanilla extract
2 c. all-purpose flour
1 1/4 c. pretzel m&ms

Directions:
With an electric mixer, cream the butter and peanut butter until smooth, about 1 minute.  Add the sugars and continue creaming until light and fluffy, about 1 minute more.  Add the milk and vanilla; mix until smooth.  Add the flour, and continue to mix at low speed until fluffy combined.  Stir in the m&ms.

Spoon the cookie dough onto the cooled brownies and spread gently into an even layer.  Slice into squares and enjoy.