In a large bowl, whisk together the 2 cups oat flour, ½ cup granulated sugar, 1 tablespoon baking powder, ½ teaspoon ground cinnamon, and ½ teaspoon fine sea salt. Work in the ½ cup unsalted butter with your hands until crumbles form.
In a small bowl, whisk together the 2 large eggs and ⅓ cup plain yogurt. Add this mixture to the dry ingredients and stir just until combined. Gently stir in the 1 cup semisweet chocolate chips. The dough will be very wet. To make it more workable, place the bowl of dough in the fridge for about 20-30 minutes.
When the dough has firmed up a bit, place a piece of parchment on the counter, sprinkle it with oat flour, then take the dough out of the bowl and place it on the paper. Pat it into a 1" thick circle and cut into it 8 triangular scones. Place on the prepared baking sheet, then place the baking sheet in the freezer for 30 minutes.
Preheat the oven to 375°F. Bake for 20 minutes, or until lightly browned and a toothpick or cake tester inserted into a scone comes out dry. Cool completely on a rack.
Notes
Start with cold butter. Use butter straight from the fridge to make your scones, or even better, keep a few sticks of butter in the freezer so they'll be ready the next time you want to make scones.
Make the dough ahead. You can prepare the scones, place them on a baking sheet, and store them, tightly covered, in the fridge or freezer for up to 24 hours.
Don't overwork the dough. While there isn't any danger of over-activating the gluten in the flour through kneading because there's no all-purpose flour in the mix, it's still a good idea to go light on your handling of the dough. This will lead to more tender scones.
Use gluten free all-purpose flour. You can substitute 2 ¾ cups of gluten-free all-purpose flour for the combination of the oat flours if needed.
Dairy-free. Substitute non-dairy butter and yogurt for the butter and yogurt.
Add a glaze. Drizzle some maple syrup over the tops of the scones right when they come out of the oven for an easy glaze, or make my maple glaze for a more robust flavor.