Place the puff pastry slices next to each other and allow to thaw. Peel and quarter the pears, cut out the core. Dice flesh. Mix with lemon and apple juice, sugar and cinnamon in a saucepan, simmer for about 8 minutes.
Stir pudding powder and 4 tablespoons of water until smooth, use to thicken the juice. Bring to the boil briefly and pour into 4 ovenproof cups or bowls. Cut out puff pastry slices so that the diameter is slightly larger than the diameter of the cups or bowls.
Cut a hole of approx. 1 cm from the centre of each one. Cut out dough residues into circles (1 cm Ø). Spread the lid and the edges of the bowl with whisked egg yolk. Decorate the lid with small circles and place on the bowls or cups.
Bake in the preheated oven (electric range: 200 °C/ convection oven: 175 °C/ gas: level 3) for 8-10 minutes until golden brown. Serve with vanilla ice cream.