Pro Tips: For tall crowns, fill muffin tins to the very top with this thick batter. Do not overmix – stir just until combined. Sour cream (or yogurt) is key for the perfect texture. Measure flour correctly by spooning and leveling. Bake at 375°F for the perfect golden color. For sparkly tops, sprinkle with a little extra sugar before baking. If using frozen blueberries, do not thaw them first.