Purge the pine cones of dirt and bugs by soaking them in a bucket of cold water for 1 hour. Keep the pine cones submerged the whole time.
Remove the pine cones from the water and lay them out on paper towels. Allow the surface water to drain out for one or two hours.
Place the pine cones on a cookie sheet. Bake them in a 200 F oven for 30 to 45 minutes, until they are dry and open. Allow the pine cones to cool and continue to dry overnight.
Mix 1 part flour and 3 parts water in a saucepan. Bring it to a boil, then remove it from the heat, stirring frequently, until it thickens into a paste. Allow the paste to cool.
Add 1 cup of ground cinnamon to a large zip top plastic bag while the paste cools.
Coat the pine cones with the flour paste with a foam brush.
Place the coated pine cones, two or three at a time, in the zip top bag filled with cinnamon. Close the bag and shake it to coat them.
Place the cinnamon-coated pine cones on wax paper. Allow the pine cones to dry for two or three days before using them.