Preheat oven to 400 degrees.
Whisk together the oat (or whole wheat) flour, baking powder, baking soda, brown sugar, salt and cinnamon in a large bowl, then transfer that mixture to the bowl of a food processor.
Add the oats and pulse in short 1-second bursts about 15 times.
Drop in pieces of cold butter and pulse again in short bursts until coarse meal forms, about 15 pulses.
Transfer this mixture back into the large bowl.
In a separate bowl or liquid measuring cup, whisk together the milk, yogurt and maple syrup.
Pour the liquid into the flour/oat/butter mixture and stir gently with a fork until it’s moistened and starts to come together.
Using your hand, gather the dough into a ball right in the bowl and knead it a few times against the side of the bowl to bring the dough together.
Turn the dough out onto a lightly floured surface and pat it into a ¾-inch thick circle.
Using a sharp knife, cut like a pie into 8 wedges.
Place the wedges on a baking sheet lined with parchment paper.
Whisk together 1 T. milk and 1 T. maple syrup in a little bowl.
Brush the tops of the scones with this mixture, then sprinkle the remaining 2 T. oats across the tops.
Bake for 15-17 minutes until tops are golden brown.
Cool on a rack.