Preheat the oven to 425 degrees F.
Brush the insides of each acorn squash with 2 tablespoons melted butter and then sprinkle on the brown sugar, salt and pepper. Place in roasting pan and bake for 45 to 50 minutes or until the flesh of the squash is fork tender. Remove from the oven and swirl the liquid around the flesh of the squash and coat it well, trying to use up all the sauce/butter that formed while baking, then discard any remaining liquid.
While the squash the squash is baking also bake the chicken. Place the chicken in a baking dish and toss with 1 tablespoon olive oil and a pinch of salt and pepper. Bake for 15 to 20 minutes or until the chicken is no long pink in the middle. During the last 10 minutes of cooking add the chopped spinach to one side of the baking dish and toss with a drizzle of olive oil. Place back in the oven until the spinach is wilted, about 5 -10 minutes. Remove from the oven and allow to cool 10 minutes, then shred the chicken with two forks or your hands.
In a medium size bowl combine the remaining olive oil, lime juice, garlic, chipotle peppers, fresh cilantro, oregano, cumin, chili powder, cinnamon, salt and pepper. Set aside.
Mix the spinach, chicken, cooked couscous and chipotle sauce together. Now grab the acorn squash halves and stuff with the chicken mixture, top with shredded cheese and bake for 10 minutes or until the cheese has melted and acorn squash is crisp.
While the squash bakes make the brown butter bread crumbs. Heat a heavy-bottomed sauce pan over medium heat, add the butter. Melt butter over medium heat until just browned. Butter will melt, foam, and froth, then begin to brown along the bottom. Quickly remove from the stove and whisk about 30 seconds longer. Let sit 2 minutes and them stir in the Panko bread crumbs.
Remove the acorn squash from the oven and top with fresh cilantro and the browned butter bread crumbs. Devour!
The squash can be made ahead, stuffed and then refrigerated until ready to eat. Just bake as directed.