Preheat oven to 425 degrees F and line a baking sheet with parchment or a silicone liner.
Cut cheese slices into 11/2 in squares and slice jalapeños (mild=thinly, hot=thickly, I recommend using a mandoline)
Arrange slices of cheese roughly 1 inch apart on your baking sheet and top with a slice of jalapeño.
Bake in the middle of the oven for 10-15 minutes. The exact time will be determined by how thick your cheese/jalapeno slices are and the baking sheet you use. Check them occasionally, remove when they are firm and very lightly brown.
Remove the pan from the oven and allow to cool for 5 minutes (the crackers will become crispy) Transfer to a cooling rack to cool completely before storing in an air tight container for roughly 3 days (ours never last longer than 24 hours since we can't stop eating them)
To bake multiple pans at once, rotate racks every 3 minutes for even baking.