In a large bowl, mix together the canola oil, egg and sugar.
In a separate bowl, sift together the flour, baking soda, salt, cinnamon and baking powder.
Add the dry ingredients to the wet ingredients and mix just until combined.
Fold in the chopped apples.
Spray an 8x8 pan with cooking spray.
Spread this mixture in the bottom of the prepared pan.
Sprinkle the walnuts and butterscotch chips on top of the cake batter.
Bake at 350 degrees for 35-40 minutes or until a toothpick inserted in the center comes out clean.
Allow the bars to cool and cut them into squares.
This cake is best baked one day before serving.
The calories shown are based on the cake being cut into 12 pieces, with 1 serving being 1 slice of cake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**