Now that you have gathered the ingredients, let’s get started on the steps to making these delightful muffins.

Preheat your oven to 350°F (175°C). This step is crucial as it ensures your muffins cook evenly.

Line a 12-cup muffin tin with paper liners or spray with non-stick cooking spray to prevent sticking.

In a large bowl, whisk together the flour, sugar, baking powder, baking soda, salt, and cinnamon. Make sure there are no lumps. This step integrates your leavening agents evenly throughout the flour.

In a separate bowl, combine the melted butter, milk, eggs, and vanilla extract. Use a whisk to blend these ingredients until fully combined. The melted butter should be cooled slightly before mixing to prevent cooking the eggs.

Pour the wet mixture into the dry mixture. Use a spatula to gently fold the ingredients together until just combined. Be careful not to overmix; a few lumps are perfectly fine.

In a small bowl, combine the flour, brown sugar, cinnamon, and cubed butter. Use your fingers or a pastry cutter to incorporate the butter until the mixture resembles coarse crumbs.

Spoon the muffin batter into the prepared muffin tin, filling each cup about ¾ full. Sprinkle the streusel topping generously over each muffin.

Place the muffin tin in the preheated oven and bake for 15-18 minutes, or until a toothpick inserted into the center comes out clean.

Once baked, allow the muffins to cool in the tin for about 5 minutes before transferring them to a wire rack to cool completely.