Place the puff pastry slices next to each other and let them thaw for about 15 minutes. Place 5 slices on top of each other. Roll out into a rectangle (20 x 30 cm) on a floured work surface. Halve the rectangle once lengthwise. Cut again crosswise into 12 strips.
Roll out 1 puff pastry sheet thinly and cut out butterflies for decoration. Mix egg yolk and milk. Spread the puff pastry sheets and butterflies with it. Sprinkle with sugar crystals. Put the strips and butterflies on 2 baking trays lined with baking paper. Bake the trays one after the other in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for about 10 minutes until golden brown. In the meantime, beat the whipped cream and sauce powder until stiff with the whisks of the hand mixer. As soon as the puff pastry has cooled down, pour the vanilla cream into a piping bag with a star-shaped spout. Spray vanilla cream spirally onto all slices.
Bake the trays one after the other in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for about 10 minutes until golden brown. In the meantime, beat the whipped cream and sauce powder until stiff with the whisks of the hand mixer. As soon as the puff pastry has cooled down, pour the vanilla cream into a piping bag with a star-shaped spout. Spray vanilla cream spirally onto all slices. Sprinkle with 1 teaspoon of fruit spread and place 2 strips on top of each other. Decorate with butterflies