Preheat oven to 375 degrees and line 12-cup cupcake tin with cupcake liners.
In a medium bowl, stir together 1 1/4 cups flour, brow sugar, cinnamon, and nutmeg. Drizzle over melted butter and mix well. Set aside
In a large bowl, stir together flour, baking powder, and salt.
In a separate medium bowl, stir together eggs, sugars, yogurt, oil, lemon zest and vanilla. Add wet ingredients to dry ingredients, stirring to combine. Gently fold the blueberries into the muffin batter.
Fill liners 2/3 full with the batter and top with streusel topping.
Bake 18 to 20 minutes, or until a toothpick comes out clean when inserted in the center.
Cool in pan for 10 minutes before removing to cool completely on a cooling rack.
Use a preheated oven.
You can use cupcake liners like shown, or you can easily use silicone muffin pans or simply spray the cups with nonstick cooking spray.
I prefer using liners, especially if I plan to take them to share with others.
The key to light fluffy muffins is to avoid over mixing.
Once they are done baking, allow them to cool a few minutes before removing from the muffin tin.
These are wonderful by themselves, but I love slicing one open and adding fresh real butter to the middle.