Make the blackberry chia pudding (no-cook): In a jar or sealable container, mash half the blackberries with a fork. Add chia seeds, almond milk, maple syrup, and a pinch of salt. Stir well, cover, and refrigerate for at least 4 hours or overnight. Before serving, top with remaining blackberries.
For the one-pot blackberry oatmeal: In a camp pot, bring 1 cup water and 1 cup almond milk to a gentle boil. Stir in oats and a pinch of salt. Reduce heat and simmer for 5 minutes, stirring occasionally. Fold in the remaining blackberries and cinnamon. Cook 2 more minutes until berries soften. Sweeten with maple syrup to taste.
For the campfire foil packet: Tear off a 12x12-inch sheet of heavy-duty foil. Place 1 cup blackberries in the center, drizzle with 1 teaspoon maple syrup, and sprinkle with cinnamon. Fold foil into a sealed packet. Place on hot coals or a camp stove grate for 8-10 minutes until berries release juice. Let cool slightly before opening. Serve alone or over oatmeal.