Honeyed Bread-and-Butter Pickles

1 pound cucumbers

1/2 medium onion (around 1/3 pound)

5 teaspoons kosher salt, divided

1 teaspoon celery seeds

2 cups cider vinegar

1/2 cup water

1/4 cup honey

1 teaspoon mustard powder

1 cinnamon stick

Slice cucumbers into 1/4 inch rounds. Thinly slice onion into half-circles. Put the customers and onions in a medium bowl and sprinkle with 4 teaspoons salt. Cover with later of ice cubes and refrigerate for 8 hours or overnight. 

Pick out any unmelted ice, drain well, and rinse under cold running water. Toss with celery seeds. Priest a quart jar in canning pot with boiling water.

Combine the vinegar, water, honey, mustard powder, cinnamon stick, and remaining 1 tsp salt in a medium pot. Bring to a boil. 

Pack the cucumbers and onions into quart jar. Ladle the hot vinegar mixture into the jar, leaving 1/2 inch headspace. Unless processing/pasteurizing, wait until jar has chilled to room temperature, then put in fridge. Wait at least 1 day, and ideally 3 days to allow flavor to develop before eating.