I have quite a few blueberry muffin recipes on my blog. Blueberry Cream Cheese Muffins and Blueberry Breakfast Cake and Blueberry Banana Banana Bread with Brown Butter Glaze.
Preheat oven to 350°F. Spray or butter a cast iron skillet.
Bake until muffin tops are golden and just firm, 17 to 19 minutes at 350°F.