Prepare the crust: In a medium bowl, combine the crushed Oreo cookies with the melted butter. Stir until the crumbs are well moistened and resemble wet sand.
Form the crust: Press the Oreo mixture evenly into the bottom of a 23x23 cm baking dish to form a firm layer. Use the back of a measuring cup to create a smooth surface. Place the dish in the refrigerator while preparing the filling.
Make the cheesecake filling: In a large mixing bowl, beat the softened cream cheese with an electric mixer until smooth and creamy.
Add sweetness: Gradually add the powdered sugar and vanilla extract, mixing until well combined. Scrape down the sides of the bowl to ensure all ingredients are evenly incorporated.
Whip the cream: In a separate mixing bowl, whip the heavy cream until stiff peaks form.
Combine the mixtures: Gently fold the whipped cream into the cream cheese mixture until well combined, being careful not to deflate the cream.
Fill the crust: Pour the cheesecake filling evenly over the chilled Oreo crust and smooth the top with a spatula.
Decorate: Scatter mini Oreos over the cheesecake layer for added crunch and decoration.
Chill: Cover the baking dish with plastic wrap and refrigerate for at least 4 hours or overnight until the filling is set.
Cut into pieces and serve: Once set, remove from the refrigerator, cut into squares, and enjoy these decadent Oreo cheesecake bars!