Peel and cut the fruit in dice-size cubes. Place the fruit in a large saucepan on medium heat as you go, starting with the apples and finishing with the pears. Add in half the amount of each spice. Let the fruit cook, stirring occasionally, on medium low heat, until most of them have mashed into compote, but some bits remain. When the compote is ready, it will have a glassy sheen, and won’t be too liquid.
While the fruits are cooking, preheat the oven at 350°F/180°C. Place in the bowl of a food processor the flour, the brown sugar, and the other half of the spices. Pulse a couple times before adding the butter chopped in large chunks. Mix until the contents are forming a crumbly melange - it doesn’t have to be fully homogeneous.
Pour the compote in a glass or ceramic baking dish at least 2 inches (5cm) deep. Mine is about 10 in (25cm) long by 4.5 in (11cm) wide. Flatten the top of the compote, then sprinkle the crumble on top. You might have to break up large chunks of dough with your fingertips, but be careful to leave some as biting in a crispy bit of dough is half the fun of this dessert (the other half is biting into a chunk of fruit that will melt in your mouth).
Place the baking dish in the oven for 15 min, then turn on the broil on low. Leave the crisp in for another 2 min. Keep a close eye on it! You’ll want the top of the crumble to be a toasty brown, but not become charcoal.
The Apple Pear Crisp can be served warm, then be covered, placed in the fridge, and consumed cold for up to a week. A quick 15 seconds in the microwave will work if you want to eat the leftovers warm.
For an extra indulgent dessert, serve the crisp warm with vanilla ice cream.
As far as the apples go, my preference is to tart apples, as they will express a lot of natural sweetness when cooking. I would also recommend you wait for your pears to be fully ripe, meaning soft to the touch and juicy when peeled. I’m looking at you, US weirdos: pears are not meant to be bit into like apples! They should melt in your mouth and make a mess.
Spices-wise, the above is my personal choice. Feel free to adapt proportions to your liking, as well as add or subtract spices (ginger and allspice are other popular options).