Place a small plate in the freezer. Wash, dry, and pit the cherries. Weigh them to make sure you have 1 kg/ 2.2 lbs. If you have more or less, weigh the sugar to make sure you have the same amount of sugar as well, so a ratio of 1:1.

Place cherries, sugar, lemon juice, and spices (if using) in a large, wide thick-bottomed pot or Dutch oven. Stir gently to mix and slowly bring to a boil. Turn the heat down to medium-low and simmer the cherries for 50-60 minutes. Skim the foam forming on top regularly. Stir gently from time to time, about every 5 to 10 minutes.

Start checking after 50 minutes already. Pour a few drops of the syrup onto the cold plate from the freezer. If the drops keep their shape and remain separated when you push your finger through them, the candied cherries are ready.

If they reunite after being pushed, prolong the cooking time. Place the plate back in the freezer and check again after 5 minutes or so. The liquid will still look thin, but it will thicken once it is completely cool.

Divide the cherries and their syrup between the sterilized jars. Let cool completely and store in a dark cool place (cellar) or in the refrigerator. They will keep for about 1 year.