First, make your cookie dough balls. In the bowl of a stand mixer, cream together the butter, brown sugar and granulated sugar together until creamy, about 1 minute. Beat in the milk and vanilla, followed by the peanut butter, then the flour until dough comes together and is sticky. Beat in the old-fashioned oats, followed by the mini chocolate chips and mini M&M's.
Using a cookie dough scoop, scoop rounded cookie dough balls and place on a parchment-lined baking sheet. You should get about 30 balls of dough. Freeze until firm, about 30 minutes.
Once dough balls are firm, make your bombs. Take a square of fudge brownie and gently flatten it in the palm of your hand. Place a cookie dough ball in the center of the flattened brownie, and use your fingers and hands to pinch the brownie around the dough ball to seal it completely, rolling the brownie bomb in your hand if needed. Return to the baking sheet, noting that you may now need 2 baking sheets as the brownie bombs are larger than the cookie dough truffles.
After the brownie bombs are made, melt the chocolate CandiQuik according to package instructions. Once melted and smooth, stir in 2 Tbsp of creamy peanut butter until blended. Dunk each brownie bomb into the chocolate-peanut butter mixture using a fork and coating all sides. Allow excess to drip off, then return to the baking sheet and repeat with remaining bombs. NOTE: You MAY need TWO (2) packages of CandiQuik to coat all the bombs, hence why the ingredients says 1-2 pkgs and 2-4 Tbsp creamy peanut butter.
Melt the vanilla CandiQuik according to package instructions and drizzle over the chocolate bombs. Immediately garnish with chopped mini M&M's. Serve!
NOTE: If you do not want to use raw all-purpose flour, you may heat treat your flour by baking it at 350 degrees F for about 10 minutes, or use different flour substitutes, such as almond flour, oat flour, coconut flour, or oat flour.