Apple Crumble Cake with Caramel and Apple Icing Recipe

Ingredients

• 3 Cox or Granny Smith apples, peeled, cored and cut into small cubes
• 8 ounces (1 cup) plus 3 tablespoons caster (superfine) sugar, divided
• 9 ounces (2¼ sticks) unsalted butter, softened, plus extra for greasing
• 3 medium eggs
• 2 cups self-rising flour
• 1/2 teaspoon baking powder
• 1/4 teaspoon ground cinnamon
• 1¼ ounces (1/3 stick) unsalted butter
• 2 ounces (1/3 cup) all-purpose flour
• 1 heaping tablespoon soft light brown sugar
• 1 ounce (1/3 cup) chopped hazelnuts
• 2 Cox apples, peeled, cored and thinly sliced
• 1 ounce (2 tablespoons) caster (superfine) sugar
• 9 ounces (2¼ sticks) unsalted butter, softened, divided
• 7 ounces (1/2 a 13.4-ounce tin) dulce de leche or caramel
• 5 ounces (1 cup) powdered sugar