Position rack in lower third of oven and preheat to 400°F. Butter muffin pan and lightly dust with tapioca flour, knocking out excess.
2
In large bowl, whisk together tapioca flour, cornmeal, rice flour, cornstarch, sugar, baking powder, baking soda, and salt.
3
In medium bowl, whisk together butter, milk, maple syrup, and eggs.
4
Using wooden spoon, stir wet ingredients into dry ingredients until fully combined. Gently fold in blueberries.
5
Divide batter among muffin cups, filling each cup 3/4 full. Bake until tops are domed and feel springy to the touch, and toothpick inserted in center comes out clean, about 15 minutes. Let cool in pan 5 minutes, then turn out onto wire rack.
