1 orange, quartered and seeds removed (with peel)
1/2 cup orange juice
1 large egg
1/2 cup butter or 1/2 cup margarine
1 3/4 cups all-purpose flour
3/4 cup white sugar
1 teaspoon baking powder
1 teaspoon baking soda
Preheat oven to 400F; grease muffin tin(s) and set aside.
Put orange quarters in food processor (or blender) along with orange juice and process or blend until pureed.
Add egg and butter to food processor and combine; pour into large bowl.
Combine dry ingredients together in a separate bowl, then add all at once to orange mixture.
Stir to combine.
Fill muffin cups about 3/4 full.
Bake in preheated oven for 20 minutes; remove from oven and let stand in tin for 5 minutes before removing muffins.