Pit and dice peaches (peel if you want; this can be quickly done by submerging the peaches in boiling water for a minute or two, then dunking in ice water and the peels will slip right off) and toss them along with sugar and spice into a large pot, such as a dutch oven.
Heat until the peaches start to break down a little, then get out a potato masher and mash up the peaches a bit.
Continue to cook (and mash, if desired) until jam reaches desired consistency.
Pour into freezer jars and screw on lids. When cool, label and stick in the freezer until ready to use.