Preheat oven to 400F and line a baking sheet with parchment paper
In a large mixing bowl, combine all purpose flour, maple sugar, baking powder, baking soda, cinnamon and kosher salt. Keep butter in the fridge until you are at this point. Cut cold butter into cubes and pour into the bowl. Mix into the dry ingredients with a pastry cutter or the back of a fork until you are left with smaller crumbles of butter.
Pour in the cold milk and mix in with a wooden spoon. Mix in the chopped pecans and then pour the dough onto a lightly floured surface. Mix together with your hands until it JUST comes together - we don’t want the dough to get warm.
Roll or shape into a 7” x 9” rectangle that is about 1” thick. Cut into 9 smaller rectangles and then cut each of those on a diagonal so you are left with 18 triangles.
Carefully place the triangles on the baking sheet with a bit of space between them. Place in the oven and bake at 400F for 14 minutes. Remove from the oven and allow the scones to cool completely.
While the scones are cooling, prepare the glaze. Heat butter and maple syrup together in the microwave for about 45 seconds or until the butter is just melted. Whisk the butter and maple syrup together until smooth then pour into a shallow bowl.
Whisk in the sifted powdered sugar until you are left with a smooth glaze. When both the scones and the glaze are cooled. Dip the top of each scone into the glaze to coat it and then place on a wire rack for the glaze to harden.
Notes
Keep the butter cold. This is the single most important rule for flaky scones. Work quickly and if your hands are warming up the dough, pop it in the fridge for 10 minutes before cutting.Do not overwork the dough. Mix just until the dough comes together and stop. Overworking develops gluten and makes the scones tough instead of tender and crumbly.Use a sharp cutter or knife. Press straight down when cutting the scones without twisting. Twisting seals the edges and stops the scones from rising properly.Glaze after cooling slightly. Let the scones cool for at least 10 minutes before adding the maple glaze. If they are too hot the glaze will melt right off. If you want a thicker glaze, wait until they are fully cool.