These bakery-style blueberry muffins prove frozen berries can rival fresh. The secret is keeping the berries frozen until the last possible moment, which prevents them from bleeding into the batter and creates pockets of intense blueberry flavor throughout each muffin. A sprinkle of sugar on top adds a delightful crunch.
Preheat the oven to 400ºF. Line 10 standard-sized muffin cups with liners. Add 2 tablespoons of water into the empty muffin cups without liners so that the muffins will bake more evenly.
Whisk together the flour, baking powder, ¾ cup sugar, and salt in a large bowl.
Place the canola oil into a 2-cup measuring cup. Crack the egg into the measuring cup, then add enough milk to reach the 1-cup mark on the measuring cup. Add in vanilla extract. Whisk to combine the wet ingredients. Pour the mixture into the bowl with the flour mixture; stir the ingredients with a fork, being careful not to overmix. Add the frozen blueberries to the batter; gently fold in.
Spoon and divide the batter into the 10 liners. Top the batter of each muffin with a sprinkling of the extra sugar. Bake the muffins for 15 minutes or until a toothpick inserted into the middle of the muffins comes out clean. Move the muffins to a cooling rack.
If you have leftover muffins, you can store them at room temperature for up to 3 days inside a sealed plastic bag.