Preheat oven to 350 and line a baking sheet with parchment paper. In a mixing bowl, add oats, oat flour, almond meal, baking powder, cinnamon (if using), and sea salt. Mix through. Add vanilla, yogurt, sugar or maple syrup, extract (if using), and mix through. Finally, fold in add-ins (see note) until just combined. Use an ice cream scoop to measure and place scoops of the batter on prepared baking sheet, yielding 10-12 buns. Sprinkle the unrefined sugar over the tops of the buns. Bake for 16-18 minutes, until golden and set to the touch. Remove, and let cool for a couple of minutes on the baking sheet and then transfer to a cooling rack to cool more. Enjoy warm or cooled.