Preheat the oven to 350°F (175°C). In a medium bowl, combine graham cracker crumbs, sugar, and melted butter. Press the mixture evenly into the bottom of a 9-inch springform pan. Bake for 10 minutes, then remove from the oven and allow it to cool while preparing the filling. Pressing the crust firmly and evenly is key for a sturdy base that holds the creamy filling without crumbling.

In a large mixing bowl, beat the cream cheese with sugar until smooth and creamy. Add eggs one at a time, mixing well after each addition. Mix in sour cream, heavy cream, key lime juice, vanilla extract, and lime zest until fully incorporated. Be careful not to overmix to avoid air bubbles, which can create cracks on top of the cheesecake.

Wrap the bottom of the springform pan in aluminum foil to prevent leaks. Place the pan in a larger roasting pan and pour hot water into the roasting pan until it reaches halfway up the sides of the springform pan. This water bath helps prevent cracking and ensures even baking. It might seem like an extra step, but it’s essential for a flawless cheesecake.

Pour the filling over the crust and smooth the top with an offset spatula. Bake at 350°F (175°C) for 60 minutes, or until the center is almost set but still slightly jiggly. Turn off the oven and let the cheesecake cool inside for 30 minutes before removing it from the water bath. This gradual cooling helps prevent sudden temperature changes that can crack the cheesecake.

Remove the cheesecake from the water bath and let it cool to room temperature. Refrigerate for at least 4 hours, preferably overnight, to allow the flavors to meld and the texture to set properly. Cheesecake tastes even better the next day as the flavors become more pronounced.

Whip heavy cream with powdered sugar until stiff peaks form. Spread or pipe over the chilled cheesecake. Garnish with lime slices or additional zest for a beautiful presentation. The whipped cream adds lightness and balances the tartness of the key lime.

Carefully remove the sides of the springform pan and slice the cheesecake. Serve chilled for the perfect creamy, tangy dessert experience. For added flair, drizzle a little raspberry or passionfruit puree on top for color contrast and extra flavor.