Defrost the strawberries in a tall mixing bowl at room temperature. Place the rolls on a baking tray lined with baking paper and cut them crosswise. Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 10-15 minutes. For the jam, roughly puree the strawberries. Add jam sugar and mix with whisk of hand mixer for 45 seconds. Remove the rolls and let them cool down. Cut the roll open and brush with butter and jam
30 minutes waiting time