Blueberry Streusel Muffins

My sister made these and normally I do not like blueberry muffins but these are actually great. They are adapted from Sally's Baking Addiction and I just have to say that I admire her so much and she has great recipes!

STREUSEL:

INGREDIENTS:

1/2 cup packed dark or light brown sugar
1 teaspoon ground cinnamon

DIRECTIONS:

Super easy: mix the sugar and cinnamon together until there aren't clumps left

MUFFINS:

INGREDIENTS:

1/2 cup unsalted butter, softened to room temperature
1/2 cup granulated sugar
1/4 cup packed light or dark brown sugar
1/2 cup yogurt (any type is good)
2 large eggs at room temperature
2 teaspoons vanilla extract
1 and 3/4 cups all-purpose flour
1 teaspoon baking powder
1 teaspoon baking soda
1/2 teaspoon salt
1/2 teaspoon cinnamon sugar
1/4 cup milk (any kind)
1 and 1/2 cups blueberries (fresh blueberries are great but if you use frozen ones do not thaw them)

DIRECTIONS:

Beat the butter on high with a paddle attachment in a stand mixer or a handheld mixer for about 2 minutes until it's thick and creamy
Add the sugars and continue to beat for another 2 minutes
Add yogurt, eggs and vanilla extract and beat on medium for 1 minute and then turn it up to high until it is completely combined
In a large bowl mix together the flour, baking powder, baking soda and salt
Combine wet and dry ingredients with a whisk
Add milk and continue to whisk until there are close to no clumps
Fold in the blueberries with a spatula or wooden spoon (the batter can be purple in some places because the blueberries bleed but it's very cool once it bakes)
Put 1 tablespoon of batter into the muffin tins, put some streusel on top of the batter and then add more batter until the liners are completely full
Bake for 5 minutes at 425F degrees and then bake for another 20 minutes at 350F degrees (you might have to bake a little more or until an inserted cupcake comes out clean)