Preheat oven to 350 degrees. Spray three 5x3" mini bread pans with nonstick cooking spray, and line the bottoms with parchment paper. Peel and dice apples, set aside.
Cream oil, butter, and sugar in a large mixing bowl. Beat in the egg, milk, vanilla. Stir in flour, salt, and baking powder just till moistened. Gently fold in the apples.
Divide batter between the three pans.
Combine all topping ingredients in a small bowl. Mix together with a pastry cutter or fork till crumbly. Sprinkle over the batter.
Bake loaves for 25-30 minutes or until a toothpick inserted in the middle of the bread comes out clean.
Cool loaves in pans for 5-10 minutes, then remove to wire racks to cool completely.
Notes
You can make a large loaf instead of 3 mini loaves. Prepare an 8 inch loaf pan as directed. Bake for 55-60 minutes at 350°.