5 granny smith apples, peeled, cored and cut into 3cm pieces
3 tablespoons brown sugar
2 tablespoons water
3 tablespoons of your favourite jam (I used raspberry and rhubarb)
110 grams cold butter, chopped
⅓ cup brown sugar
1⅓ cups plain flour
1 cold egg yolk
1–2 teaspoons cold water
¾ cup plain flour
½ cup brown sugar
½ cup rolled oats
80 grams cold butter, chopped
26cm loose-based tart tin
Filling: Put apple chunks in a large frying pan with brown sugar and water. Cook over a medium heat for 15 minutes until the apples are just soft and the water evaporated, then set aside.
Pastry: Preheat the oven to 180˚C. Pop butter, brown sugar and flour in a food processor and whiz to form breadcrumbs, add yolk and 1 teaspoon of water and pulse until the mixture forms large clumps (add extra water only if needed). Tip out on to a clean bench and pat and squash together into a pastry disc. Cover in plastic wrap and refrigerate for 15 minutes.
Remove from the fridge and roll pastry out on a lightly floured bench. Release from the bench if necessary with a spatula and fit into a 26cm loose-bottomed tart tin. Press into the sides and base, patching any holes and trimming away any excess pastry. Prick the bottom lightly with a fork and put in the freezer for 5 minutes. Put a large circle of baking paper into the pastry base and fill the tart tin with baking beans or rice. Bake for 12 minutes, remove the baking paper and baking beans and cook a further 8 minutes.
Crumble: While the base is cooking put all of the crumble ingredients in a food processor and pulse to form big clumpy breadcrumbs.
Once the base is cooked, spread jam on top of the pastry, tip in apples and sprinkle with crumble topping, squishing some of the crumble into lovely big lumps. Bake a further 25 minutes then rest for 20 minutes before removing from the tin. This can be made in advance, removed from the tin when cold and reheated for 10 minutes in the oven, but is also great at room temperature. Serves with a big scoop of vanilla bean ice cream.