In a small cup, add the 1 tablespoon of water and instant coffee powder. The coffee doesn't need to entirely dissolve - it's just to help with the process.
In a large bowl, beat together the cream cheese, sugar and coffee dissolved in water until the cream cheese is soft with no lumps. Turn off the mixer and scrape down the sides and bottom of the bowl.
Beat in the vanilla and sour cream.
With the mixer on low speed, beat in the eggs 1 at a time until just combined.
Place the springform pan with the crust (still wrapped in aluminum foil) in the middle of the large roasting pan.
Pour the cheesecake batter over the crust, smoothing the top.
Pour very hot water into the roasting pan so that there's about ½ - 1 inch of water in the roasting pan (1-2 cm).
Place the whole thing in the oven and bake for 50-60 minutes, or until the top looks just set except for in the very middle. If you give the pan a gentle nudge, the cheesecake should still have a slight wobble in the middle (think like jello or pudding).
Remove the roasting pan (with the cheesecake inside) from the oven. Cool the cheesecake in the roasting pan until the cheesecake is room temperature.
Cover the pan with aluminum foil and place in the fridge to chill for at least 6 hours, or overnight.