Preheat the oven to 350°F (175°C).
In a medium bowl, combine the graham cracker crumbs and melted butter.
Press the mixture evenly into the bottom of muffin liners in a muffin tin.
In a large mixing bowl, beat the softened cream cheese until smooth.
Add the sugar, eggs, and vanilla extract. Mix until well combined.
Fold in the diced apples and ground cinnamon.
Spoon the cheesecake mixture over the crusts in the muffin tin.
In a separate bowl, combine oats, brown sugar, and salt for the topping.
Sprinkle the oat topping evenly over each cheesecake.
Bake in the preheated oven for 18-22 minutes until the filling is set.
Allow the cheesecakes to cool before serving.