Preheat oven to 350° F (180°C). Line a 24-count muffin pan with mini cupcake liners.
In a mixing bowl, combine graham crumbs, butter and sugar with a fork until evenly moistened.
Add a heaping teaspoon of the crumbs mixture into each liner. Firmly press the crumbs down into the base.
Bake for 5 minutes. Remove from the oven and prepare the filling.
Mix cornstarch and water in a small bowl until smooth. Set aside.
Place the cream cheese in the bowl of an electric mixer, beat on low speed for 2-3 minutes until smooth and free of any lumps. Add sugar and sour cream and continue mixing until incorporated. Gradually add sweetened condensed milk and beat, scraping down the bowl as necessary, until creamy, for 1-2 minutes. Add lemon juice, vanilla extract, heavy cream and cornstarch mixture; beat on high speed, until well incorporated.
Divide the batter between all the liners. It’s about 1 tablespoon per cheesecake.
Bake for 15 – 18 minutes, or until the edges are set and the centers only slightly jiggle.
Set the pan on a wire rack and allow cheesecakes to cool at room temperature for 30 minutes, then transfer to the refrigerator and chill for at least 2 hours. The cheesecakes will slightly sink in the middle. It gives you room for toppings!
Cover and store leftover cheesecakes in the refrigerator for up to 5 days.