Preheat and Prepare Pan: Preheat your oven to 325°F (160°C). Grease a 9-inch springform pan.

Make the Crust: In a bowl, combine Oreo cookie crumbs and melted butter. Press the mixture firmly onto the bottom of the prepared pan. Bake for 10 minutes. Remove and let cool.

Prepare the Filling: In a large bowl, beat cream cheese and sugar until smooth. Add melted chocolate and peppermint extract, mixing well. Mix in flour until just combined. Add eggs one at a time, mixing on low speed just until blended.

Bake the Cheesecake: Pour the filling over the cooled crust. Place pan on a baking sheet and bake for 55-60 minutes or until center is set. Remove from oven and run a knife around the edge of the pan to loosen. Cool on a wire rack for 1 hour, then refrigerate for at least 4 hours or overnight.

Prepare the Ganache: In a saucepan, heat heavy cream until it begins to simmer. Remove from heat and add chopped chocolate, stirring until smooth. Allow ganache to cool slightly, then pour over the chilled cheesecake.

Garnish: Sprinkle crushed peppermint candies over the ganache-topped cheesecake.