Preheat the oven to 350°F. Line two large baking sheets with parchment paper and set aside. Chop up 3-4 of the Oreos and the mini chocolate chip cookies, then set aside. (Leave 10 of the Oreos whole to stuff in the cookies).
In the bowl of a handheld mixer or standing mixer with the paddle attachment, beat the butter and sugars together until light and fluffy (about 1-2 minutes). Mix in the egg, food coloring, and vanilla extract.
Add in the flour, salt, and baking soda, and mix until just combined (don't over-mix). Fold in the chocolate chips, chopped Oreos, and chopped mini chocolate chip cookies.
Scoop 10 heaping tablespoons of dough onto each baking sheet. They should be fairly big (these are monster sized cookies!). Press a whole Oreo cookie slightly into the dough, then add more dough on top to cover the Oreo completely. The cookies will weigh around 3 oz once assembled.
Bake the cookies one tray at a time in the preheated oven for 8-10 minutes, until edges and top look set. Let cool on the baking sheet for 10 minutes, then transfer to a cooling rack to finish cooling.
Please Note: I highly recommend using a kitchen scale to weigh your dry ingredients. Metric measurements are found above under the "Metric" tab.Measuring Flour: Be sure to properly measure your flour using either a kitchen scale or by fluffing it up in the bag with a fork, then using a spoon to scoop the flour into the measuring cup and then use the back of a butterknife to level it off (the is the scoop and level method)Tiktok Variation: If you want to make these cookie monster cookies the way they make them on the viral Tiktok video, leave out the Oreos and chocolate chip cookies in the dough. Follow the step by step instructions as written, then instead of placing a whole Oreo into the dough, place 2-3 pieces of milk or semisweet chocolate on top of the first ball of dough.To Leave Out the Oreo filling: Feel free to also make these are regular-sized cookies without the Oreo stuffed inside. This recipe will make around 20 regular-sized cookies, and the bake time will be the same (8-10 minutes).Mini Chips Ahoy: You can also use regular sized Chips Ahoy cookies, chopped into pieces. Please note that if you follow a dairy free diet, be sure to read the labels! You can use the Enjoy Life brand dairy free mini cookiesStorage and Freezing:Store the cookies in an airtight container or ziploc bag at room temperature for 5-6 days.The baked cookies can be frozen in a freezer bag for up to 2 months. Thaw at room temperature when you're ready to eat them.