Start by preheating your oven to 400°F (200°C) and lining a baking sheet with parchment paper or a silicone baking mat to prevent sticking.
In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, baking powder, salt, and ground cinnamon until evenly combined.
Add the cold, cubed unsalted butter to the dry mixture. Using a pastry cutter or fork, cut the butter into the flour mixture until it resembles coarse crumbs with pea-sized pieces. This step is key to achieving flaky scones.
Fold in the diced apples gently, distributing them evenly throughout the flour-butter mixture.
In a separate bowl, whisk together the heavy cream, egg, and vanilla extract until smooth. Pour this wet mixture into the dry ingredients and stir just until combined. Be careful not to overmix; the dough should hold together but stay slightly crumbly.
Turn the dough out onto a lightly floured surface. Gently pat it into a 7-inch circle about 1-inch thick. Using a sharp knife, cut the dough into 8 equal wedges.
Transfer the wedges to the prepared baking sheet, spacing them slightly apart. Bake for 18-22 minutes or until golden brown and a toothpick inserted in the center comes out clean.
While the scones bake, whisk together the pure maple syrup and a splash of heavy cream (about 1 tablespoon) in a small bowl until smooth.
Once the scones come out of the oven, immediately brush the tops with the maple glaze. Let them cool on a wire rack before serving to allow the glaze to set perfectly.