Make the Crust:
Preheat the oven to 325°F (163°C). Line a 9×13-inch cake pan with aluminum foil or parchment paper, leaving a 2-inch overhang. Spray with non-stick spray and set aside.
In a medium bowl, combine Oreo crumbs and melted butter. Press the mixture into the bottom of the prepared pan.
Bake for 10 minutes, then set aside to cool.
Make the Chocolate Cheesecake Filling:
Melt the chocolate in a large heat-safe bowl over a saucepan of simmering water, stirring until smooth. Remove from heat and let cool.
In a large bowl, beat the cream cheese on low speed until smooth and creamy.
Add granulated sugar, brown sugar, cocoa powder, and cornstarch, and beat until fully combined and smooth.
Add sour cream, heavy cream, and vanilla, mixing until smooth. Slowly mix in the melted chocolate.
Add the eggs and yolk one at a time, beating on low speed until just combined. Avoid overmixing.
Pour the filling over the cooled crust and bake for 30-35 minutes until the edges are set and the center slightly jiggles.
Remove from the oven and cool completely on a cooling rack. Run a knife around the edges to loosen. Cover with plastic wrap and refrigerate for at least 4 hours or overnight.
Make the Sweetened Whipped Cream:
In a medium stainless steel bowl, whip the chilled cream, powdered sugar, and vanilla until soft peaks form.
Assemble the Cheesecake Bars:
Remove the cheesecake from the refrigerator and carefully lift it out of the pan using the overhanging foil.
Option 1: Spread the whipped cream evenly over the cheesecake, then spoon the cherry pie filling on top. Sprinkle with chocolate shavings and slice into bars.
Option 2: Slice the cheesecake into bars first, then pipe whipped cream around the edges using a piping bag fitted with a star tip. Fill the centers with cherry pie filling and garnish with chocolate shavings.