For the crust:
23 Oreo cookies
2 tbsp. unsalted butter, melted
For the cheesecake:
12 oz. cream cheese, at room temperature
6 tbsp. sugar
6 tbsp. sour cream, at room temperature
½ tsp. vanilla extract
¼ tsp. salt
1 large egg plus 1 egg yolk
12 Oreo cookies, roughly chopped
Preheat the oven to 325˚ F. Line an 8 x 8-inch baking dish with foil. To make the crust, place the Oreos in the bowl of a food processor. Process, pulsing, until the cookies are finely ground. Add in the melted butter and pulse until the cookie crumbs are moistened. Transfer the mixture to the prepared baking pan. Press the crumbs into an even layer over the bottom of the pan. Bake the crust for 10 minutes, then set aside and prepare the filling while maintaining the oven temperature.
To make the filling, add the cream cheese to the bowl of an electric mixer fitted with the paddle attachment. Beat on medium-high speed until light and smooth, about 2 minutes. Mix in the sugar until well combined. Blend in the sour cream, vanilla and salt. Beat in the egg and egg yolk on medium-high speed until incorporated, scraping down the bowl as needed. Stir in the chopped Oreos with a rubber spatula.
Pour the cheesecake batter over the prepared crust, smoothing the top with a spatula. Bake for about 40 minutes, until the cheesecake is set around the edges but slightly wobbly in the center. Transfer the pan to a wire rack and let cool about 1 hour to room temperature. Cover the pan and refrigerate until well chilled, about 3 hours.
To cut the bars, pull the cake from the pan by lifting the foil up out of the pan. Place on a cutting board, peel away the foil, and slice into bars. Clean the knife blade between each slice to keep the edges neat. Keep refrigerated until ready to serve.