Put the frozen marionberries (blackberries) in a medium saucepan over medium heat on the stovetop. Heat the fruit for 5-10 minutes, allowing it to break down. Give it a stir occasionally.
While the berries are heating, squeeze the juice from half of an orange. You'll need one tablespoon of juice for this recipe.
After cooking the marionberries, take them off the heat. Mash the berries to the desired consistency with a potato masher or a fork. I like to make my jam pretty smooth; there will still be plenty of texture from the seeds.
After mashing, stir in the honey, fresh orange juice, and chia seeds. Let your jam stand until it has cooled and thickened. Then put the jam into a glass jar (or jars) and refrigerate it overnight.
In the morning, you'll be ready to use your fresh Oregon marionberry jam! Any jam that you will not use in 3-4 days should be stored in a freezer-safe container in the freezer.
Hot tip! If the marionberry jam isn't thickened enough after refrigerating overnight, add more chia seeds and refrigerate again for 8-12 hours.