Make the crust

1. Preheat oven to 325°F (162°C). Add cupcake liners to a cupcake pan.
2. Combine the Oreo crumbs and melted butter. Divide the mixture between the cupcake liners and press into the bottoms.
3. Bake crusts for 5 minutes then remove from oven. Allow to cool while you make the filling.

Make the filling

1. Reduce oven to 300°F (148°C).
2. In a large bowl, beat the cream cheese, sugar and cocoa until well combined (use low speed to keep less air from getting into the batter, which can cause cracks). Scrape down the sides of the bowl as needed. It’s a thick mixture.
3. Add the sour cream and vanilla extract and beat on low speed until well combined.
4. Add the Irish cream and beat on low speed until well combined.
5. Add eggs one at a time, beating slowly and scraping the sides of the bowl after each addition.
6. Divide the batter between the cupcake liners and fill most of the way.
7. Bake cheesecakes for 12 minutes, then turn off oven and leave the door closed for another 8 minutes. You will know your mini cheesecakes are done when they look firm around the edges but still jiggle ever so slightly in the center.
8. Crack the oven door and allow cheesecakes to cool for 15-20 minutes, then put in the fridge to finish cooling.

Make the whipped cream

1. To make the whipped cream, add the heavy whipping cream to a large mixer bowl and whip on high speed until it begins to thicken.
2. Add powdered sugar and Irish cream and continue to whip on high until stiff peaks form.
3. Pipe whipped cream onto each mini chocolate cheesecake, then top with a drizzle of chocolate sauce or chocolate shavings, if desired.
4. Refrigerate cheesecakes until ready to serve. Store well covered or in air-tight container. Best if eaten within 4-5 days.