Combine the blueberries, lemon zest and cane sugar in a cast iron skillet;
In a bowl, combine the brown sugar, flour, oatmeal, cinnamon and coconut oil; Layer the crumble over the blueberries;
Place the skillet over indirect and toss a handful of wood chip onto hot coals for smoking; Close the lid and cook for 30 minutes; Serve with vanilla ice cream (optional).
