Follow these steps to create your Decadent Coffee Cheesecake:

1. Preheat Oven: Preheat your oven to 325°F (160°C).
2. Prepare Crust: In a bowl, mix graham cracker crumbs with melted butter and ¼ cup of sugar. Press the mixture firmly into the bottom of a 9-inch springform pan.
3. Bake the Crust: Bake the crust in the preheated oven for 10 minutes. Remove and let it cool while preparing the filling.
4. Beat Cream Cheese: In a large mixing bowl, beat the cream cheese until smooth and creamy using an electric mixer.
5. Add Sugar and Flour: Gradually add the remaining sugar, flour, and salt, mixing until well combined.
6. Incorporate Eggs: Add the eggs one at a time, mixing on low speed after each addition until just combined.
7. Mix in Coffee: Pour in the cooled brewed coffee and vanilla extract. Mix until smooth. If desired, add instant coffee granules for a stronger coffee flavor.
8. Add Sour Cream: Finally, fold in the sour cream until just combined. Do not overmix.
9. Pour Filling: Pour the cheesecake filling over the cooled crust in the springform pan.
10. Bake: Bake in the preheated oven for 60 minutes, or until the edges are set, and the center is slightly jiggly.
11. Cool: Turn off the oven, crack the door open, and let the cheesecake cool in the oven for about 1 hour. Then, remove it from the oven and refrigerate for at least 4 hours, preferably overnight.
12. Release from Pan: Before serving, carefully run a knife around the edges of the cheesecake to release it from the springform pan. Remove the sides of the pan.
13. Garnish: Top with whipped cream and chocolate shavings if desired.