• Preheat the oven to 350F (180C) or 325F (170C) on a convection oven (some oven s do this adjustment automatically).
• Wrap the outside of a 9-inch (23-cm) round springform pan with aluminum foil. Wrap it at least 3-4 times so that the bottom and sides are covered, and all the seems are covered at least once. Fold the foil just around the edges so that it stays in place, but isn't covering the inside of the pan (see photo in the post).

Oreo Crust

• Crush the cookies (wafers and filling) until fine crumbs. This can be done in a food processor or by placing the cookies in a freezer bag and bashing with a rolling pin.
• Mix the crushed cookies with the melted butter.
• Press the mixture into the bottom of the prepared pan, creating a slight lip around the edges of the pan.
• Bake in the preheated oven for 8 minutes. Remove from the oven. Keep the oven turned on and the pan wrapped in foil.

Cheesecake Filling

• Whisk together the instant coffee powder and Kahlua in a small bowl or measuring cup to help dissolve the coffee powder.
• In a very large bowl, beat together the cream cheese and sugar until smooth. Occasionally turn off the mixer and scrape down the sides and bottom of the bowl to ensure there are no lumps.
• Beat in the sour cream until smooth.
• With the mixer on a very low speed, beat the Kahlua and coffee mixture into the cream cheese mixture. At this point, you can give the batter a small taste test. If you feel the Kahlua flavor isn't quite strong enough for you, optionally mix in 1-2 extra tablespoons of Kahlua.
• In a small bowl, whisk together the 3 eggs and 2 additional egg yolks. Then beat the eggs into the cream cheese mixture in about 2-3 additions, turning off the mixer and scraping down the sides and bottom of the bowl after each addition. Stop mixing as soon as you no longer see pieces of eggs.

Baking and Cooling the Cheesecake

• Place the springform pan (still wrapped in foil and with the baked crust inside) in the middle of a large roasting pan.
• Pour the cheesecake batter into the pan and smooth the top.
• Pour hot water into the roasting pan until there's about 1/2-1 inch (2-3 cm) of water in the roasting pan.
• Place the roasting pan in the oven on a rack about 1/3 from the bottom. Bake for 50-60 minutes, or until when give the pan a gentle nudge the cheesecake has a wobble similar to a bowl of pudding or jelly, but not like a glass of milk.
• Remove the pan from the oven. Cool the cheesecake in the roasting pan until the water is room temperature. Then remove the springform pan from the roasting pan and place on a wire rack to cool until the pan is no longer warm to the touch (do not unclamp the pan).
• Wrap the top of the pan with foil or plastic and place in the fridge to chill for at least 6 hours or overnight.

Chocolate Ganache & Serving

• Chop the chocolate into very fine pieces and place in a heatproof bowl.
• Add the cream and Kahlua to a liquid measuring cup and heat in the microwave until almost boiling (this could also be done in a double boiler).
• Pour the hot cream and Kahlua mixture over the chopped chocolate. Let sit for 3 minutes, then whisk until smooth. If there are still lumps of chocolate, microwave for 30 seconds on medium power (not high power, which is often the default) and whisk until smooth.
• Remove the cheesecake from the oven. Remove the foil. Gently trace around the outside of the cheesecake with a thin knife and unclamp the outer ring of the springform pan. If there is condensation on top of the cheesecake, gently blot it off with a paper towel.
• Pour the chocolate ganache over the top and spread into a smooth layer. It's totally ok if it drips over the sides.
• Return to the fridge until ready to serve.
• When ready to serve, slice with a thin, sharp knife (do not use a table knife). Be sure to slice all the way through the Oreo crust. For clean cuts, wipe off the knife in between each slice.