Preheat oven to 400 degrees F (200 degrees C). Spray a 9x13-inch baking dish with cooking spray.
Place each squash half in the baking dish, cut side down.
Bake squash in the preheated oven for 30 minutes. Flip squash over and place 1 tablespoon butter and 1 teaspoon garlic into each squash. Season with salt and pepper.
Bake squash, cut-side up until tender, about 20 more minutes. Cool for about 5 minutes before serving.
