In a bowl stir together the flour, salt and butter. Mash the butter using a fork until you have pea sized pieces. You can also do this in a food processor.
Add the brown sugar and ground hazelnuts, mix to combine. Place in the fridge until needed.
Peel and core the pears, cut into cubes.
Mix the pears in a bowl with blackberries, sugar, lemon juice, van. extract and the starch.
Spread evenly in a baking dish.
Sprinkle the fruit with the crumb topping and make an even layer of about ½ an inch without pressing down.
Bake at 190 C (375 F) for about 30 mins. until golden on top.
Rest for 15-20 minutes and serve with vanilla ice cream.
Notes
The crumb topping will keep in the fridge, well wrapped, for 3 days and up to 2 months in the freezer.
You can use fresh or frozen fruits.
You can flavour the fruits with some citrus juice or a liquor of your choice. Adapted from Canadian Living.
Recipe by HatiBon English at https://www.hatibon.com/blog/2016/10/pear-blackberry-crumble/