Line a muffin tin with strips of parchment paper (adhered with a bit of oil). This will make it easier to pop out the tarts once they're set.

To a food processor, add dates, melted chocolate, and coconut oil. Blitz on high until creamy and combined. Add flour, cocoa powder, and sea salt. Process until mixture starts to come together as a dough. You should be able to press it between your fingers. Taking 2 tbsp dough at a time, press evenly into the bottom of each muffin compartment. Place in freezer while you prepare the filling.

In a microwave-safe bowl, melt dark chocolate in the microwave in 30 second intervals. Cool the chocolate to just above room temperature before whisking in coconut cream and peppermint extract. Pour filling over crust until they are about 3/4 full. (Optional): Sprinkle over crushed peppermint.

Transfer tarts to the freezer to set for 30 minutes. Store tarts in an airtight container in the freezer.