Make everyday blueberry muffins more special by using good-for-you spelt flour, oats, and ground flaxseed and finishing with a sugar glaze and a touch of lemon zest.
Preheat oven to 350 degrees. Line a standard 12-cup muffin tin with paper liners.
In a large bowl, whisk together both flours, oats, flaxseed, baking powder, and salt. In another bowl, whisk together 1/2 cup milk, eggs, butter, vanilla, and granulated sugar. Whisk milk mixture into flour mixture. Gently fold in blueberries.
Divide batter evenly among muffin cups, about 1/4 cup per scoop. Bake until a tester inserted in middles comes out with just a few crumbs, 22 to 24 minutes. Let muffins cool in pan 15 minutes, then transfer to a wire rack and let cool completely.
Whisk confectioners' sugar with remaining 2 tablespoons milk until smooth. Add additional milk if needed, a drop at a time, to achieve a drizzling consistency. Dip muffins in glaze; set on rack to drip. Grate some lemon zest directly over top of each muffin; allow glaze to set fully before eating or storing. Muffins can be stored in an airtight container up to 3 days.