Heat oven to 400 degrees F (205 degrees C). Grease bottoms only of 12 muffin cups or line with baking cups.
In a medium bowl, combine flour, sugar, baking powder, lemon zest and salt; mix well. In a small bowl, combine milk, oil and egg; blend well. Add dry ingredients all at once; stir just until dry ingredients are moistened (batter will be lumpy.)
Fill cups 2/3 full. Bake for 20 to 25 minutes or until toothpick inserted in center comes out clean. Cool 1 minute before removing from pan. Serve warm.