For the scones:
3 1/2 cups/490 grams all-purpose flour
1 cup/140 grams whole wheat flour
1 cup/160 grams quick-cooking steel cut oats
2 tablespoons/30 grams baking powder
2 tablespoons/30 grams sugar
2 teaspoons salt
1 pound cold unsalted butter, diced
1/2 cup/120 grams buttermilk, cold
1/2 cup/175 grams maple syrup (preferably Grade B)
4 large eggs, lightly beaten
1 egg beaten with 1 tablespoon of milk or cream (for egg wash) (optional)
For the glaze:
1 1/4 cups/143 grams powdered sugar
1/2 cup/175 grams maple syrup (preferably Grade B)
1 teaspoon vanilla extract
Preheat oven to 400 degrees. Line a baking sheet with parchment.
In the bowl of an electric mixer fitted with the paddle attachment, combine the flours, oats, baking powder, sugar and salt.
In a small mixing bowl or 2-cup measure, combine the buttermilk, maple syrup and eggs and beat with a fork to thoroughly combine.
With the mixer speed on low, add the cold diced butter to the dry ingredients and blend until the butter pieces are pea-sized and the mixture looks like wet sand. Stop the mixer occasionally to check the size of the butter pieces and don't be tempted to turn the speed higher. with the mixer on low speed, add the wet ingredients and mix until just combined. The dough will be sticky.
Turn the dough out on a well floured surface and pat it into a roundish shape. The dough will have pea-sized lumps of butter. Flour a rolling pin and lightly roll it until it's approximately 3/4" - 1" high for regular scones. I like my regular scones to be thicker and my minis to be thinner (1/2" - 3/4"), but that's totally up to you.
Flour a cutter (I use 2 1/2" for regular scones and 1 1/2" for minis) and cut out the scones by pushing the cutter straight through the dough without twisting and put the scones on the baking sheet. Brush with the egg wash and bake for 20-25 minutes (for regular scones) or 15-20 minutes for minis (depending on how thick they are). Scones are done when the tops are crisp and the insides are done. Let scones cool on a rack for at least 5 minutes before glazing.
To prepare the glaze, combine the powdered sugar, maple syrup and vanilla in a small bowl and combine well, making sure there are no lumps. Drizzle cooled scones with maple glaze and serve.