Prepare the Crust: First, preheat your oven to 325°F (160°C). Take your Oreo cookies and crush them into fine crumbs – a food processor makes this super easy! In a bowl, mix these crumbs with the melted butter until everything is well combined.
Bake the Base: Press this cookie mixture firmly into the bottom and slightly up the sides of a 9-inch tart pan (one with a removable bottom is ideal!). Bake the crust for just 10 minutes, then let it cool completely.
Make the Velvety Filling: While the crust cools, gently heat the heavy cream in a saucepan over medium-high heat until it's very hot with tiny bubbles around the edges, but don't let it boil.
Melt the Chocolate Magic: Place your finely chopped chocolate in a heat-safe bowl. Pour the hot cream over the chocolate and let it sit for about 4-5 minutes. This allows the heat to gently melt the chocolate.
Stir and Fill: Add the vanilla extract to the chocolate and cream mixture, then stir until it's wonderfully smooth and glossy. Pour this luscious chocolate ganache into your cooled tart crust, spreading it evenly.
Chill to Perfection: Let your tart cool and set on the counter for 2-3 hours. If you're short on time, you can chill it in the refrigerator for about 1 hour, but be aware that some condensation might appear.
Decorate and Serve: Once the ganache is firm, artfully arrange your fresh, vibrant raspberries in a beautiful circular pattern on top. Lightly dust with confectioners' sugar just before serving to add that finishing touch. Enjoy this delightful treat!