Stir together the sugar, vinegar, and spices in a pan. Bring to a quick boil, then reduce the heat to a low simmer until the sugar dissolves into a gooey syrup.

Add the peppers and mix to evenly coat them with the syrup.

Simmer them for about 4 minutes. They will darken a bit as they slightly cook and absorb some of the sugars.

Transfer the candied jalapeno peppers to cleaned jars, then fill the jars with the remaining syrup.

Cover and store in the refrigerator for up to 3 months. Let them sit for at least 1 week before eating, and they will keep for several months.