This is possibly the best gluten free muffin I've ever tasted. A bakery style blueberry muffin, made with lemon zest and juice for a lovely citrus flavor.
Preheat oven to 400°F. Line a 6-cup muffin pan with cupcake liners. Set aside. (Note: I used "Tulip" cupcake liners which I found at my local grocery store, Kroger. They are also available online. It's important to use these liners if you want your muffins to rise up as shown in the photos in this post. Otherwise, if you use regular cupcake liners, they won't rise up as much but still taste delicious.)
Place the dry ingredients in a large bowl and stir to combine. Set aside.
In a medium bowl, stir together the milk and lemon juice. Add the beaten eggs and stir to combine. Pour into flour mixture. Add melted butter and mix until combined. Fold in the blueberries and lemon zest. Pour the batter into the prepared muffin pan. Bake for 25-30 minutes. Makes a dozen muffins.
Note: Here is the recipe for My Favorite Homemade Gluten-free Flour Blend: 4 c. brown rice flour (520 g.); 2/3 c. tapioca flour (84 g.); 1 c. arrowroot flour (120 g.); 2 tsp. xantham gum (7 g.)