Combine dry ingredients.
Cut in butter + vanilla until crumbly.
Chill.
Stir together.
Preheat 350°F. Line a 9x5 loaf pan.
Whisk sugar, oil, yogurt, milk, vanilla, and vinegar.
Add remaining ingredients.
Mix just until combined.
Transfer to pan and smooth top.
Top with streusel, then cinnamon sugar.
Bake about 45 min.
Cool completely.
Whisk until smooth and pourable.
Drizzle over cooled loaf.
Let set before slicing.
