In a large mixing bowl, whisk together 2 cups of all-purpose flour, 1 tablespoon of sugar, 2 teaspoons of baking powder, 1 teaspoon of baking soda, and 1/2 teaspoon of salt. Cut in 1/2 cup of chilled, cubed unsalted butter until the mixture resembles coarse crumbs.

Stir in 1/2 cup of cold buttermilk, and gently fold in 1 diced apple and 1/2 teaspoon of cinnamon, being careful not to overmix.

In a separate bowl, beat together 8 ounces of softened cream cheese and 1/4 cup of sugar until smooth and creamy. Add 1 egg and 1 teaspoon of vanilla extract, mixing well until fully combined.

Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper.

Roll out the prepared dough on a floured surface into a rectangle about 1/2 inch thick. Cut the dough into squares, placing a spoonful of cheesecake filling in the center of each.

Fold over the corners to create a sealed bun, tucking the filling away tightly.

In a small bowl, mix together 1/2 cup of rolled oats, 1/2 cup of brown sugar, 1/4 cup of melted butter, and 1/2 teaspoon of cinnamon until crumbly.

Place the assembled buns on the prepared baking sheet, sprinkle with crumble topping, and bake for 20-25 minutes until golden brown.

Once baked, cool on the baking sheet for about 5 minutes before serving warm.