First prepare the dough for the topping. Put flour, sugar and pinch of salt in a bowl and mix by hand. Now add the cold butter piece by piece. Beat everything together with a hand mixer on high speed until it forms a thick, crumbly dough. If the dough is too runny, just add a little more flour. Place the crumble in the fridge until ready to use.
Clean and core the pears, cut them into thin slices. Put them in a bowl and add the lemon juice, sugar, a pinch of salt, the cinnamon and scratch the contents of the vanilla pod. Mix well.
Grease a medium sized baking dish well with butter. Pour the pear mixture into the dish, even it out and then crumble the topping dough evenly over it in a thick layer. Everything should be well covered. Sprinkle the flaked almonds over the top.
Bake the pear crumble for about 30 minutes until the crumble is nice and golden-brown, then remove from the oven, leave to cool slightly and serve warm.