Preheat your oven to 400°F and line a baking sheet with parchment paper for easy cleanup.

In a large bowl, whisk together flour, brown sugar, baking powder, cinnamon, and salt.

Add the cold butter to the flour mixture and use a pastry cutter or your fingers to work it in until the mixture resembles coarse crumbs.

In a separate bowl, whisk together buttermilk and egg. Pour into the dry ingredients and stir until just combined.

Fold in the apple cubes gently to distribute them evenly throughout the dough.

Turn the dough out onto a lightly floured surface and shape into a round disk. Cut into 12 wedges.

Place the wedges on the prepared baking sheet and bake for about 15 minutes or until golden brown.

While the scones are baking, prepare the glaze by whisking together powdered sugar, milk, and vanilla extract until smooth.

Once the scones are done, let them cool slightly before drizzling with the vanilla glaze.