2 cups sifted all-purpose flour
2 ½ teaspoons baking powder
2 tablespoons sugar
¾ teaspoon salt
1/2 cup chilled butter or margarine, cut into ¼-inch pieces
2 eggs, well beaten
¾ cup milk
1 teaspoon grated orange zest
1 ½ cups fresh or frozen blueberries
Preheat oven to 400 degrees. Lightly grease a muffin pan. In a large bowl, combine flour, baking powder, sugar, and salt. With a pastry blender or two knives, cut in butter or margarine until particles are the size of small peas; make a well in the center. In a small bowl, combine eggs and milk; add all at once to the well in flour mixture, stirring just until moistened. Fold in orange zest and blueberries.
Fill prepared muffin cups ⅔ full. Bake 25 to 30 minutes or until golden brown. Remove from oven and immediately remove from pan. Serve warm or at room temperature.