Preheat oven to 350 degrees. If using Irresistable Peanut Butter Cookies recipe bake at 375 degrees.
In a large bowl, combine cookie ingredients as directed on package or according to your own recipe instructions.
Shape dough into 1" balls (about 2 1/2 tsp) and place 2" apart on an ungreased cookie sheet.
Bake about 8 minutes (at this time I just slightly press on cookie and return to oven for 2 more minutes) or until the edges a lightly golden brown (do not over cook or they will crumble in chocolate) cool for 2 minutes on cookie sheets them remove to cooling rack and cool completely.
In a bowl, microwave chocolate chips, peanut butter and butter uncovered on high in one minute intervals, stirring after each minute, until it is combined and smooth, stir in vanilla.
In a gallon size ziploc bag place 1 1/2 c powdered sugar; set aside.
In a large bowl place 12 cooled cookies, pour 1/3 of chocolate mixture over cookies in bowl, with a rubber spatula carefully toss cookies to coat with chocolate (they do not have to be completely coated in chocolate) Place cookies six at a time in powdered sugar bag and gently turn to coat cookies.
Shake excess powdered sugar off and place on cooling rack to set up.
Repeat with 12 more cookies and 1/2 of remaining chocolate mixture; repeat again until all cookies have been coated, adding more powdered sugar to bag if you run out.
*If you are using your own recipe, it may yield more or less cookies so make sure you have enough chocolate mix and powdered sugar to coat. The Irresistible Peanut Butter Cookies recipe makes a bit more, but I just top extra's with granulated sugar and skip steps 5+. Betty Crocker's cookie mix will make 3 dozen, which is what this recipe is based on*.