Preheat oven to 400°F (200°C) and line a baking sheet with parchment paper.
In a large bowl, whisk together flour, sugar, baking powder, and salt.
Add the cold cubed butter and cut it into the flour mixture using a pastry cutter or fork until the mixture resembles coarse crumbs.
In another bowl, whisk together heavy cream, maple syrup, egg, and vanilla extract.
Pour the wet ingredients into the dry ingredients and mix gently until a soft dough forms.
Turn the dough onto a lightly floured surface and shape it into a circle about 1 inch thick.
Cut the dough into 8 wedges and place them on the prepared baking sheet.
Bake for 15–18 minutes, or until the scones are lightly golden.
Allow the scones to cool slightly.
In a small bowl, whisk together powdered sugar, maple syrup, and milk to make the glaze. Drizzle over the cooled scones before serving.