Apple Crisp

This is a great Apple Dessert....all the great flavors from an Apple Pie without the crust, what could be easier, a must try Recipe. Topped with Ice Cream and drizzled with Caramel Sauce,
Ingredients
Topping:
1/2 cup Brown Sugar,
1/2 cup Rolled Oats,
3 oz chopped Walnuts,
1/2 tsp Baking Powder,
1 tsp Cinnamon,
1/4 tsp Salt,
6 tbsp cubed cold Butter,
1/2 cup Flour,

Filling:
5 large Granny Smith Apples, peeled, cored & diced,
1/2 cup Sugar,
1/4 cup Brown Sugar,
3 tbsp Cornstarch,
1/4 tsp Salt,
1 tsp Cinnamon,
1 tsp Vanilla,
2 tbsp melted Butter,
1 tsp Lemon Juice,