To begin making filling, preheat oven to 180°C. In a large skillet, heat the fireball, sugar, lemon juice and spices over medium heat until simmering. Simmer for 15 minutes or until reduced by half. Pour over the chopped apples, transfer to a baking dish or pie tin and put into the oven to bake for 30 minutes or until apples are softened.
To prepare crumble topping, combine dry ingredients in a bowl and mix well. Add the butter and rub through with your hands until well combined. Transfer to a baking sheet and bake in prepared oven for 15 minutes. Cool slightly, then bash pan against the bench to break into a rough crumble.
To make butterscotch sauce, place fireball, salt and sugar into a small pan over medium and bring to a boil. Reduce heat slightly and continue at a controlled boil for 10 minutes stirring regularly or until reduced and starting to darken. Remove from heat and stir through milk and butter. Allow to cool slightly then serve on the side.
To serve, spoon apple mixture into bowl and top with a generous amount of crumble and a scoop of ice cream.