Preheat oven to 325°F (165°C) and grease a 9x13 (23x33 cm) baking pan. Prepare the brownie mix in a bowl.

In a separate bowl, mix together the cream cheese and the sugar until there are no lumps.

Add the egg and vanilla, stirring until evenly combined.

Spread the brownie batter in an even layer on the bottom of the pan.

Place 24 of the sandwich cookies in a single layer on top of the brownie batter. To fill in the edges, cut 6 of the cookies in half and nudge those in.

Pour the cheesecake batter on top, spreading it evenly over the cookies.

Crush the remaining 6 cookies and sprinkle on top of the cheesecake batter. Bake for about 45 minutes, until the edges are slightly golden brown and the middle is slightly jiggly.

Cool and chill for at least 2 hours. Slice and serve! Enjoy!