Prep the pan: Line the bottom of a 9-inch (23 cm) springform pan with parchment. Lightly grease the sides for a cleaner release.
Make the crust: Stir cookie crumbs, melted butter, sugar (if using), and salt until evenly moistened.
Press firmly into the pan, going slightly up the sides. Use the bottom of a measuring cup to compact it well. Chill while you make the filling.
Dissolve the coffee: Mix instant espresso with hot water until smooth.
Let it cool to lukewarm. This ensures even flavor without melting the filling.
Optional gelatin step: Sprinkle gelatin over cold water and let it bloom for 5 minutes. Microwave for 10–15 seconds until just melted, or warm gently on the stove.
Cool slightly before adding later. This helps the cheesecake hold extra-firm slices, especially in warm climates.
Beat the cream cheese: In a large bowl, beat cream cheese, powdered sugar, vanilla, and salt until completely smooth and fluffy. Scrape the bowl so there are no lumps.
Add the coffee: Beat in the cooled dissolved coffee. Taste and adjust coffee strength.
For a bolder flavor, add another 1/2–1 tsp espresso powder, dissolved.
Whip the cream: In a separate bowl, whip cold heavy cream to medium-stiff peaks. Don’t overbeat. You want it cloud-like but stable.
Combine: Gently fold the whipped cream into the coffee-cream cheese mixture in two additions.
If using gelatin, whisk a few spoonfuls of the cheesecake mixture into the melted gelatin to temper it, then fold that back into the main bowl.
Fill the pan: Spoon the filling over the chilled crust. Smooth the top with an offset spatula. Tap the pan gently to release any air bubbles.
Chill: Cover and refrigerate at least 6 hours, but overnight is best for a clean slice and fully developed flavor.
Serve: Run a thin knife around the edge and release the springform.
Dust with cocoa, add chocolate shavings, or pipe whipped cream. Slice with a hot, dry knife for the neatest edges.