Slice the jalapeños into rounds using food-safe gloves and a sharp knife.
Add the sugar, apple cider vinegar, garlic powder, celery seed, turmeric, and crushed red pepper flakes to a dutch oven over medium-high heat. Bring to a boil then reduce heat and simmer for 5 minutes, stirring occasionally.
Add the sliced jalapeños and bring the mixture to a boil then reduce to a simmer and cook, stirring occasionally, for 5 minutes.
Using a slotted spoon, remove the jalapeños from the pot and place them into a glass jar.
Bring the remaining liquid up to boil to reduce the mixture, cooking for approximately 5 minutes.
Carefully ladle syrup into the glass jar over the jalapeños. Let cool completely, cover with a lid, and store in the refrigerator for a few days before eating (if you can refrain).
They can be stored in the refrigerator for up to three months.