Start with the crust. Crush those chocolate cookies until they’re the texture of wet sand. Melt some butter (this is where a rich, good-quality option really shines) and mix it all together, pressing firmly into a tart or pie pan. Chill this until it’s set—no cracking, no crumbling.

Melt and blend your chocolate base. In a double boiler or gently over low heat, melt chocolate with another splash of butter. Add a shot of whiskey, cocoa powder, vanilla, and the smallest pinch of salt. Make sure everything’s combined and glossy, but don’t overheat—chocolate is temperamental. Pour over the chilled crust and let it set so the first forkful breaks cleanly through both layers.

Build the coffee custard filling. Whisk together eggs, brown sugar, white sugar, cocoa powder, cornstarch, espresso powder, and salt until smooth and creamy. Warm milk in a pan, then slowly whisk it in (think of making a perfect crème pâtissière, but with the boldness of coffee and chocolate). Add more melted chocolate for good measure. Once thick and dreamy, let it cool a little—then spread over the chocolate layer, smoothing to the edges.

Bake, then chill. The pie needs a gentle bake until just set—a little wobbly in the center is perfect. Chill for a long stretch; this is what gives you neat slices and a layered look that’s obscenely inviting.

Whip the cream topping. Combine well-chilled cream with powdered sugar and Irish cream. Whip to soft peaks—cloud-like and utterly spoonable. Spread or pipe over the cooled pie and finish with chocolate shavings, espresso powder, or even a drizzle of whiskey if you’re feeling wild.