Preheat oven to 325 degrees.
Crush Oreo cookies in a zip top bag until you have fine crumbs. A rolling pin or meat mallet works great.
Mix with melted butter.
Scoop about a tablespoon of cookie crumb mixture into mini cheesecake pan.
Press with the back of a spoon or a shot glass.
Mix softened cream cheese with an electric mixer until smooth.
Add sugar, egg, Kahlua and Bailey's Irish Cream, mixing until well combined.
Melt dark chocolate chips in a microwave safe bowl.
Add melted chocolate to cheesecake mixture, beating until combined.
Add sour cream and mix well.
Scoop cheesecake batter over cookie crust.
Bake for 25 minutes.
Remove from oven and cool on a wire rack.
Run a sharp knife around edges of cheesecakes and remove from pan.
Make Ganache by combining dark chocolate chips, Kahlua and Bailey's Irish Cream in a microwave safe bowl.
Microwave 30 seconds and stir, repeat in 15 second intervals until chocolate is melted and smooth.
Spoon ganache over mini cheesecakes.
Refrigerate for 2 hours or until ready to serve.