Preheat the oven to 325°F (163°C). Line a standard 12-cup muffin pan with paper cupcake liners.
Mix the graham cracker crumbs, melted butter, and sugar in a bowl until the crumbs look like wet sand. Divide the mixture evenly among the liners and press it firmly into the bottom of each cup.
Bake for 5 minutes, then remove the pan from the oven and let the crusts cool slightly. Beat the softened cream cheese and sugar in a large bowl until smooth and creamy. Scrape down the sides of the bowl to remove any lumps.
Add the eggs one at a time, mixing on low speed after each addition. Mix in the sour cream, vanilla extract, flour, and lemon juice until everything is combined. Avoid overmixing, as too much air can cause the cheesecakes to crack.
Divide the cheesecake filling evenly among the prepared crusts, filling each liner about three-quarters full.
Bake for 18 to 22 minutes, or until the edges look set and the centers still have a slight jiggle. Turn off the oven and leave the cheesecakes inside with the door slightly open for about 5 minutes.
Remove the pan and let the cheesecakes cool for 30 minutes. Transfer them to the refrigerator and chill for at least 3 hours, or until completely set.
Add the chopped strawberries, sugar, and lemon juice to a small saucepan over medium heat. Cook for 5 to 7 minutes, stirring occasionally, until the strawberries soften and release their juices.
Stir in the cornstarch slurry and cook for another 1 to 2 minutes, until the mixture thickens. Remove from the heat and let the topping cool completely before using.
Once the cheesecakes are fully chilled, spoon the cooled strawberry topping over each one. Carefully remove the paper liners and arrange the cheesecakes on a serving plate.
