Preheat the oven to 350 degrees F. Line two muffin tins with 18 muffin liners. Set the tins aside.

In a food processor or blender, grind the Oreos up into fine crumbs. Add the crumbs to a medium-sized bowl, along with the butter. Stir until they are combined.

Divide the cookie crumbs/butter mixture evenly among the muffin liners (~1 heaping tbs per liner) and press them into the bottom.

Bake for 5 minutes and allow it to cool slightly.

In the bowl of a stand mixer (or in a large bowl, with the aid of a handheld electric mixer), beat the cream cheese until totally smooth. Scrape down the sides of the bowl.

Add the sugar and yogurt, beating on medium speed until it is combined.

One at a time, add the eggs, beating on low speed. Once combined, add the vanilla extract and Irish Cream liqueur and beat a little more.

Divide the batter evenly among the lined muffin cups. Bake 20-23 minutes, or until the centers are just slightly jiggly.

Allow the cheesecakes to cool to room temperature before stashing them in the fridge to chill overnight (or for at least 2 hours).

Place the chopped chocolate in a medium-sized bowl. Set aside.

Gently warm the cream in a saucepan over medium heat until it begins to gently simmer. Be sure to not allow it to come to a boil.

Pour the heated cream over the chocolate. Allow it to sit for 2-3 minutes.

Using a rubber spatula, stir the chocolate and cream together until glossy and smooth.

Add the Irish Cream liqueur and stir to combine.

Allow the ganache to sit for just a bit so that it thickens slightly. Spoon it over the cooled cheesecakes.

Garnish with mini chocolate chips, if desired.