Halve the lemons lengthwise. Remove the flesh with a spoon. Set aside the emptied lemon halves, squeeze the flesh by hand. Reduce the juice with sugar to half (about 0.8 dl) until syrupy. Strain the syrup. Add double cream and mix well. Fill the lemon halves with the mixture. Chill for 2-3 hours.
Evenly sprinkle cream with raw sugar. Caramelize sugar to light brown with a blowtorch. Decorate with mint leaves.