Preheat your oven to 325°F (160°C). In a mixing bowl, combine crushed chocolate cookies with melted butter, stirring until fully coated. Press this mixture firmly into the bottom of a greased 9-inch springform pan and bake for 8–10 minutes until set, then let it cool completely.

In a large mixing bowl, beat the softened cream cheese using an electric mixer on medium speed until smooth and creamy, about 2-3 minutes. Gradually add granulated sugar, mixing until fully incorporated. Add room temperature eggs one at a time, mixing in the vanilla extract, sour cream, and cooled brewed espresso.

Once the filling is smooth, gently fold in the all-purpose flour if using. Pour the filling into the cooled cookie crust, tapping the pan gently to release any air bubbles.

Wrap the outside of the springform pan with aluminum foil to prevent water from seeping in. Place the pan inside a roasting pan, filling the roasting pan with hot water halfway up the sides of the springform. Bake in the oven for 60–70 minutes until the edges are firm, and the center still jiggles slightly.

While the cheesecake cools, heat the heavy cream in a saucepan over medium heat until simmering. Pour the hot cream over chocolate chips, letting it sit to melt, then stir in brewed espresso until smooth.

Cover the cheesecake with plastic wrap and refrigerate for at least 4–6 hours, or overnight for best results. Garnish with optional whipping cream, chocolate shavings, or coffee beans before serving.