These bars are easy to make for a snack or dessert. They can be individually wrapped and frozen for school lunches, or served warm with or without ice cream after dinner.
Stir together oatmeal, whole wheat flour, brown sugar, baking soda and salt.
Cut butter into small squares and toss with flour mixture. Cut in with pastry blender or two knives (or in bowl of food processor) until the mixture looks like coarse crumbs.
Sprinkle the oil over and mix in with a fork.
Set aside 1-1/4 cups of the mixture in a small bowl. Stir nuts (if using) into this reserved topping.
Press the remaining flour mixture into the prepared baking pan.
Bake for 15 minutes at 350 degrees F / 176 degrees C.
While base is baking, prepare the filling.
To prepare filling:
Combine the 1/3 cup / 80 ml brown sugar, all-purpose flour, cinnamon, raisins or cranberries, beaten egg and chopped apples in mixing bowl. Stir until thoroughly blended.
To assemble bars:
Spread apple filling over the baked base.
Top with the mixture that has been set aside.
Return bars to oven and bake for an additional 30 minutes, or until the bars are golden brown.
Remove from oven, and let bars cool before cutting into bars.