Mix the flour, sugar, brown sugar, salt, vanilla and butter in a bowl until you can form crumbs with fingers.
Put the apple mixture into the pan and cover with foil.
Put the topping on a cookie sheet lined with parchment.
Bake both the filling pan and the sheet with crumbs for 15 minutes.
After 15 mins, remove the foil from the filling.
Also, take out the topping and break it up with a spatula.
Carefully dump the crumbs on the filling and bake uncovered for about 30 minutes.