Preheat oven to 400 degrees F. Line a baking sheet with parchment paper. Set aside. In a large bowl, mix together flour, brown sugar, baking powder, salt and cinnamon.
Add grated butter to the mixer and cut together with a pastry cutter or two forks, until it resembles course sand.
Add 1/2 cup heavy cream, vanilla extract and shredded apple. Mix until it just comes together. Lay out a pastry mat or piece of parchment paper. Dump mixture onto the mat or parchment paper and gently pat into a 1/2-inch thick circle. Cut into 8 even triangles.
Place scones 2 inches apart on the prepared baking sheet. Brush with remaining 2 tablespoons of heavy cream. Bake for 15 to 20 minutes, until light golden brown.
While scones are baking, make the maple glaze. Add powdered sugar, maple syrup, heavy cream, vanilla and salt to a bowl and whisk together until smooth. Add to a small ziplock bag. Set aside.
Once scones have cooled, snip a small corner off the ziplock bag then drizzle scones with the maple glaze. When glaze has hardened, store in an air tight container for 3 to 4 days.