"Even if you're like me and don't care for yogurt, you'll love these apple muffins," promises Cheri Huff of Litchfield, Michigan. "I sometimes individually wrap them in colored plastic wrap and tie them with a ribbon to sell at bake sales or share with others.
In a large bowl, combine the flour, sugar, baking powder, salt and cinnamon. Combine the yogurt, egg, oil and milk; stir into dry ingredients just until moistened. Stir in apple and raisins if desired (batter will be thick). Fill greased or paper-lined muffin cups two-thirds full.
For topping, in a small bowl, combine the flour, sugar and cinnamon; cut in butter until crumbly. Sprinkle over batter.
Bake at 400° for 20-24 minutes or until a toothpick comes out clean. Cool for 5 minutes before removing from pan to a wire rack.