Combine first 3 ingredients in a large bowl; make a well in center of mixture.
Beat eggs until foamy. Stir together eggs and butter; add to dry ingredients, stirring just until moistened.
Place foil baking cups in muffin pans, and coat with cooking spray; spoon batter into cups, filling two-thirds full.
Bake at 350° for 20 to 25 minutes or until done. Remove from pans immediately, and cool on wire racks.