Heat oven to 325° F. Grease and flour a 12-cup muffin tin or line with paper liners.
In a small bowl, mix apples, sugar and cinnamon. Set aside.
Combine topping ingredients in a small bowl until crumbly. Set aside.
In a mixing bowl, beat sugar and oil with an electric mixer on high speed. Reduce speed to medium and beat in egg and vanilla. Stir in flour, baking soda, cinnamon and salt until just mixed. Add apple mixture and stir to blend.
Fill prepared muffin tins three-fourths full. Sprinkle with topping mixture. Bake for 25 to 30 minutes or until muffins test done. Cool in pan on wire rack.Makes 1 dozen muffins