Chocolate Cupcakes with Peanut Butter Cookie Dough Frosting

Chocolate Cupcakes with Peanut Butter Cookie Dough Frosting  (recipe adapted from here)

For the Chocolate Cupcakes: 
NOTE:  I live at high altitude so my package directions say to add 1/3 cup flour to the mix and decrease the oil to 1/3 cup while increase the buttermilk by 2 Tbsp. so that is what I did.  If you live at sea level, the following will work for you.
• 1 (18.25 oz.) box Devil’s Food (or other chocolate variety) cake mix
• 1 cup buttermilk
• 1/2 cup vegetable or canola oil
• 4 eggs
For the Peanut Butter Cookie Dough "Frosting": 
NOTE:  I decreased the original amount of flour from 2 1/2 cups to 2 cups and increased the chocolate chips from 1 cup to 1 1/2 cups.
• 12 Tbsp. (1.5 sticks) butter, room temperature
• 1/2 cup peanut butter
• 1 cup brown sugar, packed
• 1/2 cup granulated sugar
• 1/2 cup milk
• 1 tsp. vanilla
• 2 cups flour
• 1/2 tsp. salt
• 1 1/2 cup mini semisweet chocolate chips

Mix the cups cake batter and pour into lined muffin tins, 2/3 full.  Bake at 350 for 18-20 minutes.  At high altitude bake at 375 for 16-18 minutes.  Remove from oven and cool completely.
For the frosting:
In a mixing bowl cream together the butter and sugars.  Add the milk and vanilla and mix well.  In another bowl combine the flour and salt and stir together.  Pour the flour and salt mix into the creamed mix and fold together with a spatula, do not over mix.  Add the chocolate chips and fold them in.  Spoon the mixture onto the cooled cupcakes.