Preheat Oven:Set the oven to 350°F (180°C).Line a muffin tin with paper liners or grease the muffin cups to prevent sticking.
Prepare Streusel Topping:If you're adding a streusel topping, prepare it by combining ingredients like flour, sugar, and cinnamon. Combine it and then pour in melted butter. Toss until crumbly.
Prepare Wet Ingredients:In a large mixing bowl, cream together the softened butter and sugar until the mixture becomes light and fluffy. Add the eggs one at a time, beating well after each addition. Stir in vanilla.Another option: Melt butter and mix with sugar until pale. This produces a more denser crumb texture. Combine Dry Ingredients:In a separate bowl, whisk together the flour, baking powder, baking soda, and salt. This ensures an even distribution of leavening agents.
Gradual Mixing:Gradually add the dry ingredients to the wet ingredients, alternating with the milk.Begin and end with the dry ingredients to create a well-mixed batter.Mix just until combined, being cautious not to overmix, as this can lead to dense muffins.
Fold in Blueberries:Gently fold blueberries into the batter for even distribution. Gently fold in the blueberries until they are evenly distributed throughout the batter.This ensures that the blueberries are well incorporated without breaking them apart.
Fill Muffin Cups:Spoon the batter into the prepared muffin cups, filling each about 2/3 full.
Bake in Oven:Place the muffin tin in the preheated oven.Bake for 20-25 minutes or until a toothpick inserted into the centre of a muffin comes out clean. Each oven is different so just keep an eye and test before removing.This toothpick test ensures that the muffins are fully baked.
Add Streusel Topping:When the muffins have baked for about 15 minutes, sprinkle streusel topping generously over baking muffins.This ensures that the topping doesn't sink into the batter and ensures that it retains its distinct crumbly texture.
Cooling Process:Allow the muffins to cool in the tin for 5 minutes.Transfer the muffins to a wire rack to cool completely.