Preheat oven to 400 degrees. Grease a muffin tin or line with muffin liners.
In a large mixing bowl sift together flour, sugar, baking powder, salt, and cinnamon.
In a measuring cup add 1/3 cup oil. Add egg and milk until it measures 1 cup. Add vanilla.
Add to dry mixture until well combined.
Scoop batter into muffin tins until almost full.
For topping combine flour, sugar, and cinnamon in a small mixing bowl. Cut in cubed butter with a pastry cutter until coarse crumbs. Top muffins liberally with streusel topping.
Bake for 16-20 minutes or until toothpick inserted comes out clean.