In a medium bowl, combine Oreo cookie crumbs and melted butter. Mix until the crumbs are well coated. Press the mixture firmly into the bottom of a 9x9-inch baking dish to form the crust. Refrigerate for 10 minutes to set.

In a large mixing bowl, beat the softened cream cheese with an electric mixer until smooth and creamy. Gradually add the powdered sugar and vanilla extract, mixing until well combined.

In a separate bowl, whip the heavy cream until stiff peaks form. Gently fold the whipped cream into the cream cheese mixture until fully incorporated.

Fold in the mini marshmallows, sprinkles, and chopped strawberries if using. Pour the cheesecake mixture over the chilled crust and spread it evenly.

Cover the baking dish with plastic wrap and refrigerate for at least 4 hours or until set. For best results, chill overnight.

Once set, cut into bars and serve. Enjoy the festive colors and flavors!