Preheat the oven to 275°F (135°C). Line a 12-cup muffin tin with paper liners.

In a medium bowl, combine the crushed graham crackers, granulated sugar, and melted butter. Mix until the crumbs are evenly coated.

Press about 1 tablespoon of the mixture into the bottom of each cupcake liner, creating a firm and even crust.

Bake for 8 minutes, then remove from the oven and let cool.

In a large bowl, beat the softened cream cheese and granulated sugar until smooth and creamy.

Add the vanilla extract and mix until combined.

Add the eggs and egg yolks one at a time, mixing well after each addition.

Mix in the sour cream and a pinch of salt until the filling is smooth and well combined.

Divide the cheesecake filling evenly among the prepared crusts in the muffin tin.

Bake in the preheated oven for 20-25 minutes, or until the centers are set and the edges are slightly puffed.

Remove from the oven and allow the cupcakes to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.

Once cooled, refrigerate the cupcakes for at least 2 hours, or until thoroughly chilled.

Before serving, remove the cupcakes from the refrigerator.

Evenly sprinkle about 1 teaspoon of superfine sugar over the top of each cupcake.

Using a kitchen torch, carefully caramelize the sugar by moving the flame in small circles over the surface until the sugar melts and turns a deep amber color.

Allow the caramelized sugar to harden for a few minutes before serving.