In a mixing bowl, combine graham cracker crumbs, granulated sugar, and melted butter. Mix until fully incorporated. Press the mixture firmly into the bottom of a 9-inch springform pan.

Bake at 350°F (175°C) for about 10 minutes. Allow it to cool.

In a large bowl, beat the softened cream cheese until creamy. Gradually add the granulated sugar, mixing well.

Add the eggs one at a time, mixing on low speed until combined. Next, add the sour cream, coffee granules, and vanilla extract. Mix until smooth and creamy.

Pour the cheesecake mixture over the cooled crust. Bake at 325°F (163°C) for about 50-60 minutes. The edges should be set, while the center remains slightly jiggly.

Turn off the oven and let the cheesecake cool inside for about 1 hour.

While the cheesecake cools, heat the heavy cream in a small saucepan until it just begins to simmer. Remove it from heat and add the chocolate chips. Stir until the chocolate is completely melted and combined. Allow it to cool slightly before spreading it over the cooled cheesecake.

Refrigerate the cheesecake for at least 4 hours or overnight. Before serving, top with whipped cream and a sprinkle of cocoa powder or chocolate shavings if desired.