Toffee apple sorbet with pecan rosemary crumble

Name: Toffee apple sorbet with pecan rosemary crumble
Ingredients: 8 medium apples (1.2kg), unpeeled, halved lengthways; 1/2 cup (75g) firmly packed brown sugar; 1/2 cup (110g) caster (superfine) sugar; 1/4 cup (60ml) water; 2 1/2 cup (625ml) cloudy apple juice; 1 1/2 tablespoon lemon juice; 1 medium apple; 1/4 cup (55g) caster sugar; 1/2 cup (75g) plain (all-purpose) flour; 1/4 cup (55g) firmly packed brown sugar; 60 gram (2 ounces) butter, chopped finely; 1/4 cup (30g) roasted pecans, chopped finely; 2 teaspoon chopped fresh rosemary