Preparation Steps

• Preheat oven to 325°F. Wrap a 9-inch springform pan with two layers of heavy-duty foil. Lightly grease the pan and line the bottom with parchment.
• Make the crust: In a bowl, combine graham cracker crumbs, oats, brown sugar, and salt. Stir in melted butter, peanut butter, and vanilla until evenly moistened. Press firmly into the bottom and slightly up the sides of the pan. Bake 10 minutes, then cool 10 minutes.
• Make the filling: Beat cream cheese and granulated sugar on medium speed until completely smooth and fluffy, about 2 minutes. Mix in sour cream, peanut butter, vanilla, and salt until combined. Beat in eggs one at a time on low, just until incorporated. Tap the bowl to release air bubbles.
• Make the monster cookie swirl: In a medium bowl, stir together oats, baking soda, and brown sugar. Add egg yolk, peanut butter, vanilla, and salt; stir until thick. Fold in mini M&M's and mini chocolate chips. Mixture will be stiff.
• Assemble: Pour half of the cheesecake filling over the crust. Scatter teaspoon-sized bits of the cookie swirl over the filling. Add remaining filling and dot the top with more cookie bits. Gently swirl with a butter knife without touching the crust.
• Bake in a water bath: Place the pan in a larger roasting pan and add hot water to reach halfway up the sides of the springform. Bake 60 to 70 minutes, until edges are set and the center wobbles slightly.
• Cool gradually: Turn off the oven, crack the door, and let the cheesecake rest inside for 60 minutes. Remove the pan from the water bath, discard foil, and cool to room temperature. Chill at least 6 hours or overnight.
• Ganache and topping: Heat cream until just steaming, then pour over chocolate chips. Let sit 2 minutes, then whisk smooth. Cool until slightly thickened and spread over the chilled cheesecake. Top with chopped mini peanut butter cups and extra mini M&M's.
• Serve: Run a warm knife around the edge to release, remove the ring, slice with a hot, dry knife, and serve.