Mix together the butter, salt, icing sugar, ground almonds and vanilla powder. Then add the eggs and finally the flour, then knead without overworking the dough until it is homogenous. Store in the fridge at 5°C (41°F) for at least 24 hrs before using.
Beat the butter and icing sugar until whitened, gradually add the eggs then the ground almonds, powdered cream, and pistachio paste and finish blending.
Line the 16 cm square pastry tin with the pastry up to 2 cm around the sides, then garnish with the almond cream (about 240 g per tart). Arrange the sliced pear (about 300 g per tart). Cook in a fan oven at 170°C (338°F) for about 25 min. Leave to cool and coat with a transparent glaze. Decorate with pistachios.