Coffee Cake Muffins: Irresistible Treats for Any Morning!

Preheat your oven to 375°F (190°C). Line a 12-cup muffin tin with paper liners or grease the cups with butter or cooking spray.
Mix Dry Ingredients:

In a large mixing bowl, whisk together the flour, granulated sugar, baking powder, baking soda, salt, and cinnamon.
Combine Wet Ingredients:

In a separate bowl, whisk together the melted butter, egg, buttermilk (or milk with vinegar), and vanilla extract.
Make the Muffin Batter:

Pour the wet ingredients into the dry ingredients and gently stir until just combined. Be careful not to overmix, as that can result in dense muffins.
Prepare the Streusel Topping:

In a small bowl, combine the flour, brown sugar, cinnamon, and softened butter. Use a fork or your fingers to mix everything together until the mixture resembles coarse crumbs. Stir in the chopped nuts if you’re using them.
Assemble the Muffins:

Spoon the muffin batter evenly into the prepared muffin tin. Then, sprinkle the streusel topping generously over each muffin.
Bake:

Bake in the preheated oven for 18-20 minutes, or until a toothpick inserted into the center of a muffin comes out clean. If needed, add a couple of extra minutes for larger muffins.
Cool and Serve:

Allow the muffins to cool in the pan for about 5 minutes, then transfer them to a wire rack to cool completely. Serve warm with a cup of coffee or your favorite morning beverage!
Serving and Storage Tips: