Preheat oven to 375 F. Fill a muffin tin with paper lines and set aside. Line a baking sheet with parchment paper and set aside.
Prepare the crumb topping: In a medium bowl, combine the sugars, cinnamon and salt. Whisk in the melted margarine or butter. Add flour and stir until just combined. Spread out the crumb mixture on the prepared baking sheet and set aside until ready to use.
In a second bowl, whisk together the milk, oil and eggs.
Add milk mixture to flour mixture and stir until just combined. Distribute the muffin batter evenly among the muffin cups and sprinkle the top with the crumbs. Gently press crumbs into the batter.
Bake for 15-17 minutes, or until a toothpick inserted in the center comes out clean. Set aside to cool for 10 minutes.
Prepare the glaze; in a small bowl whisk together the powdered sugar and milk until smooth. If the glaze is too thin, add more confectioners sugar,
Drizzle glaze over muffins before serving.
