Grease a 9-inch springform pan and line the bottom with parchment paper.
Preheat oven to 325°F.
Pulse Oreo cookies in a food processor until finely ground, then add melted butter and pulse until combined.
Press cookie mixture firmly into the bottom of the springform pan.
In a mixing bowl, beat cream cheese, peanut butter, and sugar until light and fluffy.
Add vanilla extract, sour cream, heavy cream, and flour; beat to combine.
Gently mix in eggs one at a time by hand to avoid adding air.
Pour cheesecake filling into the crust and smooth the top.
Wrap the springform pan with two layers of aluminum foil to seal tightly.
Place wrapped pan in a larger pan and fill larger pan halfway with hot water.
Bake cheesecake for 65 to 75 minutes until the top is matte and center slightly jiggles.
Turn off oven and keep door closed for 20 minutes, then crack door open and leave cheesecake inside another 20 minutes.
Remove cheesecake from oven, allow it to cool completely, then refrigerate for at least 3 hours.
Heat heavy cream until simmering and pour over chocolate chips. Cover and let sit for several minutes, then whisk until smooth ganache forms.
Beat butter and peanut butter until smooth for the frosting.
Add powdered sugar and mix; while beating, add heavy cream gradually until fluffy frosting forms.
Run a knife around cheesecake edges to loosen, remove springform ring, and transfer cheesecake to serving platter.
Pour ganache over cheesecake center and spread with spatula, allowing drips down sides.
Allow ganache to set 10 to 15 minutes.
Pipe peanut butter frosting swirls around cheesecake edges.
Decorate frosting swirls with buckeye balls.