Instructions

• Preheat oven to 350°F for a glass pan or 325°F for a dark pan.
• Line a 9 x 13-inch pan with parchment paper, leaving an overhang for easy removal; set pan aside.
• In a large bowl, crumble 2 cups refrigerated chocolate chip cookie dough (about 15 oz). Add 1/2 cup oats, 1 cup mini M&M's, and 1 cup Reese's peanut butter chips; stir until evenly combined.
• Press the cookie-dough mixture into an even layer in the prepared pan.
• Bake the crust for 10 minutes.
• While the crust bakes, place 14 oz sweetened condensed milk and 12 oz semisweet chocolate chips in a microwave-safe bowl. Microwave on high for 30 seconds, stir, and continue microwaving in 30-second intervals, stirring between each interval, until the mixture is smooth and fully melted. Stir in 1 teaspoon vanilla extract.
• Remove the partially baked crust from the oven. Carefully pour the warm chocolate mixture over the crust and gently spread it into an even layer with a spatula (the crust will still be soft).
• Sprinkle additional mini M&M's on top as desired (reserve some before mixing the dough if you want specific topping quantity).
• Return the pan to the oven and bake 15 to 18 minutes more, or until the edges and center begin to crack.
• Let the bars cool completely on a wire rack, then refrigerate about 1 hour to allow the fudge to set before lifting out of the pan and cutting into bars.