Preheat oven to 350°F (175°C)
Crush graham crackers into fine crumbs
Mix crumbs with sugar, then stir in melted butter
Spoon about ¼ cup of the mixture into each 8-oz ramekin and press firmly to form the crust
Beat cream cheese until smooth
Add egg yolk, whole egg, sugar, and vanilla. Mix until creamy and lump-free
Pour about 6 tablespoons of cheesecake filling into each ramekin
Place ramekins on a baking sheet and pour about 1 cup of water onto the baking sheet (this helps prevent cracking)
Bake at 350°F for 30 minutes, or until centers are set
Let cheesecakes cool for 15 minutes before eating
Add toppings if desired — cherries, caramel, chocolate, or fresh berries