Start by preheating your oven to 325°F (163°C). In a medium bowl, combine the graham cracker crumbs with the melted butter. Stir until all crumbs are moistened and the mixture resembles wet sand. Press this mixture firmly into the bottom of your 8x8 baking pan. Use the back of a spoon or a flat-bottomed glass to create an even, compact layer. Bake for 10 minutes, then remove from the oven and let it cool while you prepare the filling.
In a large bowl, beat the softened cream cheese with an electric mixer until smooth and creamy. Gradually add the sugar, mixing until fully combined and fluffy. Beat in the eggs one at a time, making sure each one is fully incorporated before adding the next. Stir in the vanilla extract and cooled brewed coffee, mixing just until blended. Set aside.
In a separate bowl, whip the heavy cream until stiff peaks form. This will add lightness and volume to your cheesecake bars.
Gently fold the whipped cream into the cream cheese mixture using a spatula. Be careful not to deflate the airy texture. Pour the filling over the cooled crust and spread it evenly with a spatula. Return the pan to the oven and bake for 35 to 40 minutes, or until the edges are set and the center slightly jiggles when you gently shake the pan.
Remove the cheesecake bars from the oven and allow them to cool to room temperature. Once cooled, place the pan in the refrigerator and chill for at least 4 hours or overnight. Before serving, dust the top generously with cocoa powder using a fine mesh sieve. Add chocolate shavings for an extra touch of indulgence if desired. Slice into bars and enjoy!