Even though it has a strong British heritage, America has embraced the apple pie to the point that it's now considered a quintessentially American dessert. American pies often look like the ones from those Desperate Dan comics – big, robust and full of attitude. The crumble-like topping sprinkled over my pie is an idea I've been playing about with, and I think it helps make it unique. Because huckleberries grow wild in Wyoming, I felt it was only right to use them, but feel free to use fresh or frozen blueberries in their place for equally delicious results. Assembling your pie is dead easy, and I'll talk you through it step by step, but if you'd like to see how it's done before you start, check out the How to video for a demonstration. 

You can make your pastry by hand, or simply pulse all the ingredients in a food processor. If making by hand, sieve the flour, icing sugar and salt from a height into a large mixing bowl. Use your fingertips to gently work the cubes of butter into the flour and sugar until the mixture resembles breadcrumbs. Transfer a handful of this mixture to a separate bowl, rub it between your fingers to get larger crumbs, then put aside. Add the eggs and milk to the main mixture and gently work it together until you have a ball of pastry dough. Don't work it too much at this stage – you want to keep it crumbly and short. Sprinkle a little flour over the pastry, then wrap it in cling film and pop it into the fridge to rest for 1 hour.

Meanwhile, put the apples into a large pan with the zest and juice of 1 orange, a splash of water and 5 tablespoons of caster sugar. Cover the pan and simmer on a medium heat for 10 minutes, until the apples have softened but still hold their shape. Remove from the heat and leave to cool. Scrunch a handful of berries in a bowl with the remaining caster sugar and the zest and juice of your remaining orange. Add the rest of the berries. Toss the cooled apples and their juices in a large bowl with the berries and the flour, then put aside.

Preheat your oven to 180ºC/350ºF/gas 4. Take your ball of pastry out of the fridge and let it come up to room temperature. Get yourself a pie dish around 28cm in diameter. Flour a clean surface and a rolling pin. Cut off a third of your pastry and put that piece to one side. Roll the rest into a circle just over 0.5cm thick, dusting with flour as you go. Roll the circle of pastry up over your rolling pin, then gently unroll it over the pie dish. Push it into the sides, letting any excess pastry hang over the edge. Tip in the fruit filling and brush all around the edge of the pastry with some of the beaten egg. Roll out the smaller ball of pastry about 0.5cm thick and use your rolling pin to lay it over the top of the pie. Brush it all over with more beaten egg, reserving a little. Sprinkle over the reserved crumble mixture and the demerara sugar.

Fold the scruffy edges of pastry hanging over the sides back over the pie, sealing the edge by twisting or crimping it as you like. Brush these folded edges with your remaining beaten egg. Using a small, sharp knife, cut a cross into the middle of the pie. Place on the bottom of the oven and bake for 45 to 55 minutes, until golden and beautiful. Serve with ice cream, cream or custard.