In a large bowl, cream together the butter and cream cheese with a hand mixer until smooth. 

Add the powdered sugar and mix until fully combined, scraping down the sides as needed. 

Mix in the egg and vanilla until well combined.

In a separate bowl, whisk together the baking powder, salt, and flour. Add to the flour mixture to the butter mixture and mix until fully incorporated, scraping down the sides as needed. 

Stir in the crushed cookies and mix until just combined.

Cover the bowl and place the cookie dough in the fridge for at least 2 hours. The dough must be very cold before baking or the cookies will spread too much.

Preheat the oven to 350°F. Place 1 tablespoon-sized balls of the cookie dough 2-inches apart onto a parchment-lined baking sheet. 

Bake for 9-10 minutes until they are just set. 

Let the cookies cool completely on the baking sheet.