Stir together the streusel dry ingredients.
Mix in the melted butter until large crumbs form.
Stir together dry muffin ingredients until well blended.
Stir together wet ingredients until fully combined.
Combine wets and dries to form a smooth batter.
Mix in half the streusel.
Portion batter evenly into a lined muffin tin.
Top generously with remaining streusel.
Bake until golden brown and fully set in the center. Share and enjoy!