Heat oven to 350°F and line a standard muffin tin.
In a medium bowl, whisk together all wet ingredients until smooth.
Add all dry ingredients to the wet mixture and gently stir with a spatula or wooden spoon until just combined. The batter will be thick but easy to scoop.
Toss the haskap berries with 2 tbsp oat flour, then gently fold into the batter.
Using a ¼ cup scoop or measuring cup, portion the batter evenly into the prepared muffin tin. Sprinkle with hemp seeds and rolled oats, if desired.
Bake for about 25 minutes, or until a toothpick comes out clean.
Let the muffins cool in the pan for 5 minutes, then transfer to a cooling rack to cool completely before storing in the fridge in an airtight container.
