Combine the vinegar, water, kosher salt, sugar, pickling spice, mustard seeds, and peppercorns in the saucepan and bring to a boil over high heat. Remove from the heat and allow to cool until just slightly warmer than room temperature.
Slice the cucumbers into 1/2-inch thick rounds. Divide them evenly between the jars. Add the garlic, jalapeños, and dill, dividing evenly between the jars.
Pour the brine into the jars making sure to cover the ingredients. Cool to room temperature and cover with lids. Store in the refrigerator, allowing the pickles to marinate for a week, then serve.