Preheat the oven to 325F (160C) and line a muffin pan with 12 muffin liners.
Pulse the crackers in a food processor until they form fine crumbs. You can also use a plastic bag and a rolling pin to crush the crackers. Add melted butter and pulse just until the mixture resembles wet sand.
Divide the mixture between the liners and press down with a spoon or the bottom of a shot glass to make it compact and flat. Set aside.
In a large mixing bowl, add the cream cheese. Mix it with a spoon or a rubber spatula until smooth and creamy.
Add the sugar, cornstarch, lemon juice, vanilla extract and salt. Whisk with a metal whisk or beat with a hand mixer on medium just until well combined.
Add eggs one at a time and whisk just until fully incorporated and the mixture has a homogenous consistency.
Add sour cream and whisk to incorporate.
Divide the mixture between muffin liners.
Bake in the middle of the oven for 20-22 minutes or until the tops are slightly puffed up and the cheesecakes are still a little bit jiggly if shaken.
Remove from the oven and let the cheesecake cool down to room temperature. Then, place in the fridge for 4-6 hours or overnight.
Remove the muffin liners from the cheesecakes and top them with jam (see Note 1 for cranberry jam recipe) of your choice, fresh berries, mint, and/or powdered sugar.