**Prepare the Crust:** Pulse the Oreos in a food processor until finely ground.

**Mix Butter:** Add the melted butter and mix until combined.

**Form the Crust:** Press the crumbs firmly into the bottom and up the sides of an 8-inch tart pan with a removable bottom.

**Chill:** Place the crust in the freezer for 15 minutes while you make the filling.

**Chop Chocolate:** Finely chop the dark chocolate and place it in a bowl.

**Heat Cream:** In a small saucepan over medium heat, combine the heavy cream, butter, powdered sugar, salt, and vanilla. Heat until just steaming.

**Combine:** Pour the hot cream mixture over the chopped chocolate. Let it sit for 1 minute, then stir until smooth.

**Fill the Crust:** Pour the chocolate filling into the prepared crust. Smooth the top with a mini offset spatula.

**Chill:** Refrigerate the tart for 2-3 hours until set. Remove from the fridge 15 minutes before serving.

**Garnish:** Dust with cocoa powder and top with fresh berries if desired. Enjoy!