This recipe was originally published in Frøken Jensen Kogebog med Syltebog back in 1936 and was found on Spise Med Mormor
1 kg ripe (not overripe) tomatoes
1 kg powdered sugar
Juice from 4 lemons
Dry the tomatoes well, prick with a darning needle and place in a jar, alternating with the sugar in layers. Let sit for 24 hours. The next day, pour the juice into a pot, add lemon juice, and bring to a boil. Pour the hot liquid over the tomatoes. Repeat the process over the next two days (heating up the juice and pouring it boiling hot over the tomatoes.) A bit of cognac can be poured into the jars on the last day before they’re sealed. Be sure to use the same hygiene rules for canning here as you would for anything else.