Preheat oven to 350 F. Line one regular muffin tin with paper liners
Mix the first 5 muffin ingredients together.
Beat Butter and Sugar together. Add in eggs one at a time.
Mix in vanilla extract, yogurt and milk.
Add flour mixture to batter, a little at a time.
Mix all streusel ingredients together. Using your fingers works great!
Fill muffin cups 1/4 full with batter Then sprinkle 1/2 of streusel topping on muffins pressing down gently into batter
TOP with remaining batter and streusel mix.
Bake for 20 minutes or until toothpick inserted in center comes out clean.