Halve peaches and remove pits. Set aside. In a food processor, grind almonds and sugar together until coarsely ground. Add oats and cinnamon, then butter, pulsing the machine until the ingredients are just blended. Spoon the almond mixture into the center of each peach half. Put two peach halves together and wrap in two layers of aluminum foil.
At camp, start charcoal or fire. (Charcoal gives you a little more control, but you can also use the coals of a fire.) Once the charcoal or fire is ready, put the peaches on top of the charcoal or coals. Bake for 15 minutes then turn and cook an additional 5 to 15 minutes until the peaches are tender.