Preheat oven to 425°F. Spray a 12-count muffin pan with nonstick spray or use cupcake liners. Set aside.
Mix all of the streusel ingredients together. Set aside.
Whisk the flour, baking soda, baking powder, and salt together in a large bowl.
Using a handheld or stand mixer with the paddle attachment, beat the butter, granulated sugar, and brown sugar together on high speed until fluffy and creamy, about 4 minutes. On medium speed, add the eggs one at a time, beating well after each addition. Beat in the sour cream and vanilla extract on medium speed until combined.
With the mixer running on low speed, add the dry ingredients and milk, alternating while adding. Starting and finishing with the dry ingredient mixture.
Beat until no lumps remains but be careful do not over mix. Fold into berries.
Spoon the batter into liners, filling them all the way to the top. Top each with streusel, gently pressing it down into the surface so it sticks.
Bake for 5 minutes at 425 then, keeping the muffins in the oven, reduce the oven temperature to 350°F.
Bake for an additional 18-20 minutes or until a toothpick inserted in the center comes out clean.
Allow the muffins to cool for 5 minutes in the muffin pan, then transfer to a wire rack to continue cooling.