Preheat the oven to 400F. Line a baking sheet with parchment paper. (See Notes, below.)
Add all the dry ingredients, including 3 tsbp maple flakes. to a large bowl and whisk together to incorporate.
In a medium bowl, whisk together the egg, yogurt, cream, and extract. Set aside.
Cut the butter into the dry ingredients until the butter is about pea-sized. The dough will have the texture of crumbs. (See Notes, below. Or see the Scones Primer for pictures.)
Add wet ingredients to flour mixture and stir until dry ingredients are incorporated.
Gently knead the dough into a ball in the bowl, then turn out and begin patting into a circle until it’s about 1 inch (2.5cm) thick. You may need to squeeze the outer edges a bit to incorporate crumbly bits into the dough.
Cut the dough into 8 evenly sized wedges and place them on the prepared baking sheet. Brush lightly with cream if desired. (This gives a nice sheen to the finished scones.)
Bake for 11-12 minutes, or until edges start to turn golden.
Let scones cool for about 5 minutes on the pan, then move them to a wire rack. Place the parchment from the baking pan under the wire rack to catch drips when you ice the scones.
After the scones have cooled for about 10-15 minutes, make the icing by whisking together all of the icing ingredients. If the icing is too thin, add more icing sugar, a teaspoon at a time. If it is too thick, add some cream, a couple of drops at a time. (See Notes, below.)
Drizzle or spread icing on each cooled scone, then sprinkle with maple flakes.