Make the crust: In a mixing bowl, thoroughly combine the graham cracker crumbs, melted butter, and brown sugar until the mixture resembles wet sand. Firmly press this mixture into the bottom and slightly up the sides of a 9-inch or 10-inch springform pan. Ensure the crust is packed tightly to prevent crumbling when sliced. For a smooth finish, use the bottom of a measuring cup to press the crust evenly. Place the crust in the freezer for 10 to 20 minutes to set while you prepare the cheesecake filling.
Make the filling: Begin by whipping the cold heavy cream in a stand mixer or with a hand mixer using the whisk attachment. Whip on medium-high speed until stiff peaks form, which should take around 4 to 5 minutes. Set the whipped cream aside.
Next, in a clean bowl, beat the softened cream cheese with the granulated sugar on medium speed until the mixture is completely smooth and creamy. Scrape down the sides and bottom of the bowl occasionally to ensure even mixing. Once smooth, add the confectioners’ sugar, sour cream, lemon juice, and vanilla extract. Continue to beat on medium-high speed for another 2 to 3 minutes until all the ingredients are well incorporated, and the mixture is silky smooth. Ensure there are no lumps of cream cheese remaining; if you find any, continue mixing until they disappear.
Gently fold the whipped cream into the cream cheese mixture using a silicone spatula or by running your mixer on a low setting. Take your time with this step to preserve the airiness of the whipped cream. It may take a few turns of the spatula to fully integrate the whipped cream into the cheesecake filling.
Retrieve the crust from the freezer and evenly spread the cheesecake filling over it. Use an offset spatula to smooth the top of the filling for a clean finish. Cover the pan tightly with plastic wrap or aluminum foil and place it in the refrigerator. Allow the cheesecake to chill for at least 6 to 8 hours, though 12 hours or overnight is ideal for the best results. The extended chill time will help the cheesecake set beautifully.
When ready to serve, run a knife along the edge of the cheesecake to release it from the pan, then remove the springform ring. Slice the cheesecake with a sharp knife, wiping the blade clean between each cut for neat slices.
Serve the cheesecake with your favorite toppings, and store any leftovers in the refrigerator for up to 5 days.