Preheat oven to 400°F. Line a baking sheet with parchment paper.
In a large bowl, whisk together flour, sugar, baking powder, cinnamon, and salt.
Cut in cold butter using a pastry cutter or fingers until mixture resembles coarse crumbs.
Stir in the diced apple.
In a separate bowl, whisk cream, egg, and vanilla. Pour into the dry ingredients and stir gently just until combined. Do not overmix.
Turn the dough onto a floured surface. Pat into an 8-inch circle, about ¾-inch thick.
Slice the dough into 8 wedges and transfer to the prepared baking sheet.
Brush the tops with cream.
Bake for 15–18 minutes or until golden. Cool slightly before serving.