Combine first 5 ingredients in a medium bowl, and make a well in center of mixture. Combine buttermilk, margarine, and egg, and stir well. Add to the flour mixture, stirring just until moistened.
Spoon about 1 tablespoon batter into each of 12 muffin cups coated with cooking spray. Spoon 1 teaspoon preserves into center of each muffin cup (do not spread over batter), and top with remaining batter.
Combine 1 tablespoon sugar and 1/4 teaspoon cinnamon; stir well. Sprinkle evenly over muffins. Bake at 400° for 20 minutes or until muffins spring back when touched lightly in center. Remove muffins from pans immediately, and place on a wire rack.
Easy and tasty.