Step 1

Preheat the oven to 350 degrees.

Step 2

Using a stand mixer fitted with the paddle attachment or a hand mixer, cream the butter, peanut butter and sugar on high for 1-2 minutes. Scrape down the bowl once complete.

Step 3

Add in egg, vanilla extract, baking soda and salt. Mix until combined. Scrape down the bowl once complete.

Step 4

Add oats in 2-3 portions, mixing after each addition. Scrape down the bowl once complete.

Step 5

Fold in the chocolate chips and m&m's using a silicone spatula or wooden spoon.

Step 6

Line the 8x8 baking pan with parchment paper (for easy removal later) and press half of the cookie dough evenly throughout the bottom of the pan. Set the rest of the cookie dough aside for later.

Step 7

Bake the crust for 8-12 minutes or until it has just begun to brown. Make the cheesecake layer while the crust cooks.

Step 8

In a stand mixer fitted with the paddle attachment or a hand mixer, beat the softened cream cheese in a separate bowl until smooth. Scrape down the bowl once complete.

Step 9

Add the sugar, vanilla extract and flour. Beat on medium-high until smooth. Scrape down the bowl once complete.

Step 10

Add in the egg and beat on low-medium until just combined. Do not over beat. Scrape down the bowl once complete and fold the batter a few times to ensure that it is mixed well.

Step 11

Pour the cheesecake batter over the cooked crust. Use a spatula to gently smooth it out. The crust can still be hot when you do this.

Step 12

Grab handfuls of the remaining monster cookie dough and use your fingers or palms to press them into as thin of a layer as possible. Evenly place the cookie dough around the pan, topping the entire cheesecake layer with the remaining monster cookie dough.

Step 13

Bake the cheesecake bars at 350 degrees for 30-40 minutes or until the topping (and the edges of the cheesecake) begins to brown. The cheesecake may still jiggle, and that's okay.

Step 14

Remove the cheesecake bars from the oven and allow them to cool to room temperature before moving them to the fridge to set (for at least 4 hours, but preferably wait overnight before you enjoy them).