Take the puff pastry out of the fridge and let it rest for about 10 minutes. Unroll the dough and roll out to approx. 26 x 45 cm. Cut out 10 circles (each approx. 10 cm Ø) from the dough. Place the remaining dough on a floured work surface, roll out again and cut out 2 more circles
Grease the muffin tray (12 wells; each with a capacity of approx. 90 ml). Line the trays with the dough circles, press them lightly and refrigerate
Slit the vanilla pod lengthwise and scrape out the pulp with the back of a knife. Put butter, milk, cinnamon stick, vanilla pulp and vanilla pod into a pot, bring to the boil and let it stand for about 5 minutes. Remove vanilla pod and cinnamon stick. Sift the flour, add sugar and salt, mix everything together and stir into the milk while stirring vigorously. Bring to the boil again, pull it down and let it cool down for about 5 minutes. Stir egg and egg yolks into the cream. Wash the nectarine, grate dry and cut into thin slices
Spread the cream into the hollows lined with puff pastry. Put 3 nectarine slices in half of the cavities (use the remaining slices for other purposes or fill all cavities with the cream). Bake in a preheated oven (electric cooker: 225 °C/ convection oven: 200 °C/ gas: see manufacturer) for 12-14 minutes. Remove the tartlets, let them cool down briefly on a cake rack and remove them from the tartlets. Sprinkle each tartlet with approx. 1/2 tsp. brown sugar and caramelise it with a gas burner or under the grill of the oven until golden brown
Waiting time approx. 30 minutes