Melt icing sugar and syrup in an ovenproof pan (16 cm Ø). Add butter and flaked almonds. Simmer at medium heat for about 5 minutes. Wash, halve and core the pear.
Cut the flesh into slices, add to the syrup and simmer for another 5 minutes. Let the slices of puff pastry thaw when placed on top of each other. Roll out to the size of the pan. Place on the caramelised pears and bake in the preheated oven (electric range: 225 °C/ convection oven: 200 °C/ gas: level 4) for approx. 15 minutes.
Let it rest for 5 minutes and carefully (hot!!!) fall out of the pan. If you like, add some more colour to the tarte with a burner.