Preheat oven to 350°F. Spray a 2.5 qt. pan with vegetable pan spray.
In large bowl, combine oats, sugar, walnuts and flour. Using a pastry blender or two forks, cut in 5 tablespoons butter until mixture forms pea-sized pieces.
For fruit filling, melt remaining 3 tablespoons butter in large skillet over medium heat. Add apples and cook, stirring occasionally, 10 minutes or until softened. Remove from heat and stir in pie filling, vanilla and cinnamon. Pour mixture into prepared pan. Sprinkle on top of apple mixture.
(In place of Braeburn apples, substitute two 20-ounce cans of apples in water, drained. Melt 3 tablespoons of butter and combine apples, butter and raspberry pie filling. Pour into prepared pan and continue with recipe as directed. )
Bake 40 to 45 minutes or until filling is bubbly and topping is golden brown.