Preheat oven to 400°.
Spray muffin pan cups with non-stick spray cooking oil (or, use paper liners).
Mix dry ingredients together in a large bowl. Use a pastry blender or fork.
In a large glass measuring cup (2 c.) or bowl, beat the egg, then add the oil and milk and mix together.
Pour liquid ingredients into the dry, then gently fold together just until dry ingredients are moist, adding any fruit pieces, nuts, etc.
Divide batter into muffin pan cups.
Bake at 400° for about 20 minutes.
Cool about 10 minutes, then lift from pan.