Jam-filled Muffins

1 3/4 cups all-purpose flour
1/2 cup sugar
1 tablespoon baking powder
1/2 teaspoon salt
2 eggs
2/3 cup milk
1/3 cup butter or margarine, melted
1 teaspoon grated lemon peel
1/2 cup raspberry or strawberry jam
DIRECTIONS:1. In a large bowl, combine flour, sugar, baking powder and salt. In a small bowl, lightly beat eggs; add milk, butter and lemon peel. Pour into dry ingredients and stir just until moistened. Spoon half of the batter into 12 greased or paper-lined muffin cups. Make a well in the center of each; add jam. Spoon remaining batter over jam. Bake at 400 degrees F for 20-25 minutes or until golden.