50g cold butter, cut into 1cm cubes, plus extra for cooking and greasing
100g plain flour, rice flour or gluten-free flour
50g demerara sugar
4 Granny Smith apples or cooking apples, peeled, cored and chopped
50g soft brown sugar
juice of 1 orange
100g granulated sugar
200ml double cream
vanilla ice cream, removed from the freezer 10 minutes beforehand, to serve
squirty cream, to serve
Preheat the oven to 170°C, gas mark 3. Grease a 20cm x 20cm baking tin with butter and line with baking parchment.
Sift the flour into a large bowl. Make a well in the centre. Using your fingertips, rub the butter cubes into the flour until the mixture resembles fine breadcrumbs. Stir in the demerara sugar.
Tip the mixture into the prepared tin, spreading it evenly over the base. Bake for 20-30 minutes, until lightly golden and crunchy on top. Remove from the oven, place the tin on a wire rack and leave to cool completely.
Meanwhile, put the apples, soft brown sugar, orange juice and 5g butter in a saucepan over a low heat. Stir, cover with a lid and cook for 10-15 minutes, stirring occasionally, until the apples are soft and fluffy. Use a potato masher or fork to mash to a fine pulp. Taste and add more sugar if needed.
When the crumble is completely cool, dip your fingertips into cold water and pinch clumps of it together to form crunchy crumble pieces.
Fill a bowl with ice and water. Put the granulated sugar and 100ml water in a small pan over a medium heat. Swirl the pan (do not stir) until the sugar has dissolved. Increase the heat and allow to bubble. As soon as the mixture turns a dark caramel colour, plunge the base of the pan into the bowl of iced water – this stops the cooking process and prevents the caramel burning. Stir in the cream and transfer to a jug.
To serve, layer sundae glasses or serving glasses with apple sauce, 1 tbsp caramel sauce, 2 tbsp crumble and a scoop of vanilla ice cream. Finish each glass with a drizzle of caramel sauce, a sprinkling of crumble and a squirt of cream.