Slice acorn squash in half, scoop out seeds, and clean the inside. Brush the inside of the squash with olive oil, lightly season with salt, black pepper, and garlic powder. Place on a baking sheet with the cut sides down. Bake for 20 minutes.
Meanwhile, heat 2 tablespoons of olive oil in a skillet, add mushrooms, sweet potatoes, bell pepper, and diced Meal Maker Bar. Season lightly with salt, pepper, and garlic powder. Cook 5-8 minutes on medium-high heat. Remove from heat, and stuff the squash halves evenly with mixture.