Preheat your oven to 325°F (160°C). Line the muffin cups or mini cheesecake pan with liners.
In a mixing bowl, combine the graham cracker crumbs and melted butter. Mix until the crumbs are fully coated.
Press the graham cracker mixture evenly into the bottom of each muffin cup to form the crust.
In a large bowl, beat the softened cream cheese and granulated sugar with an electric mixer until smooth and creamy.
Add the sour cream, eggs, vanilla extract, and lemon juice to the cream cheese mixture. Mix until fully combined and no lumps remain.
Carefully pour the cheesecake batter over the crust in each muffin cup, filling them about ¾ full.
Place the muffin tray on a baking tray and bake in the preheated oven for 25-30 minutes, or until the centers are set but still slightly jiggly.
Remove the mini cheesecakes from the oven and let them cool at room temperature for about 15 minutes. Then refrigerate for at least 2 hours, or until completely chilled.
Before serving, sprinkle a thin layer of granulated sugar over the top of each cheesecake. Using a kitchen torch, caramelize the sugar until it forms a crispy top layer. Allow a few minutes for the sugar to harden before serving.