Peanut Butter Cookies
In a separate bowl, combine the flour, baking powder and salt. Add the flour mixture and milk to the batter, alternating flour and milk until both are added. Stir just until combined. Refrigerate dough for at least 1 hour.
Shape the chilled dough into balls with your hands, and place two inches apart on a greased baking sheet (12 small cookies per sheet or 8 large cookies per sheet). Bake at 375 for 6 1/2 - 7 minutes, just until edges are starting to brown. Cool for one minute on the baking sheet, then transfer to a sheet of waxed paper on the counter and cool completely. Cookies will be very soft, and may appear to be slightly undercooked in the center, but trust me, this is how they should be. They'll finish setting up as they cool, and will remain soft and delicious.
Once the cookies are cool, make your frosting. Melt the chocolate chips using a double boiler, or in the microwave, stirring often. Transfer to a mixing bowl, and add the butter. Begin adding the powdered sugar and milk, alternating 1/4 cup powdered sugar with 1 teaspoon of milk, until you've reached a desired consistency. I made mine very thick.
Turn over half of the cooled cookies. Scoop about 2 tablespoons of the frosting onto the bottom of the cookies--it will be too thick to spread, so don't even try. Place a second cookie on top of the frosting and press down to spread the frosting out to the edges. Store in airtight Tupperware or ziplock bags to keep fresh--they will stay soft and fresh for days afterwards.
Original Blog Post: http://www.curlygirlkitchen.com/2011/07/peanut-butter-cookie-cream-pies.html