Preheat oven to 325 degrees Fahrenheit.
Line 3 cupcake pans with cupcake liners for a total of 36 servings. I serve these with the liner off, so the design doesn't matter unless you want to serve yours in the liner.
Crush the Oreos and Nutter Butters to a fine crumb. I use my food processor for this step.
Add butter, brown sugar, and vanilla to the crushed Oreo and Nutter Butter mixture. Stir together until completely incorporated.
Place one heaping tablespoon of cookie mixture into each muffin cup. Find something the size of the muffin cup to press the mixture down to create a firm bottom. I use the bottom of an aspirin container.
Soften cream cheese in the microwave for a minute. Add the sugar, sour cream, heavy whipping cream, vanilla, eggs, and peanut butter to the cream cheese. Cream ingredients together until completed combined. I do this step in my stand mixture with the paddle attachment.
Add two heaping Tbsp of the cheesecake filling mixture to each muffin cup. These will be slightly lower than the top of the tin.
Bake the cupcakes at 325 for 20-23 minutes. Remove from oven and allow to cool.
Prepare a double boiler with 2 inches of water in the bottom. If you do not have a double boiler, set a glass bowl on top of a pot with two inches of water. Bring water to a boil and then reduce heat to low.
For the ganache topping, add your semi-sweet chocolate chips and 7 Tbsp butter to the top of your double boiler. Stir until completely melted and combined.
Remove the ganache from the heat and allow it to cool, stirring occasionally. This should be glossy and thick but spreadable.
For ease of pouring, transfer the chocolate ganache to a liquid measuring cup. Pour a small amount of ganache topping onto the cheesecakes. Swirl to coat the top.
Store in a sealed container in the refrigerator until ready to serve. I peel back the cupcake liners and serve the cheesecakes exposed.