This will quickly become one of your favorite ways to prepare squash. Warning: Your kitchen will smell heavenly.
Preheat oven to 400°F. Line a rimmed baking sheet with parchment paper. Brush melted butter evenly over cut sides of squash; sprinkle with salt and pepper. Fill squash cavities evenly with thyme, sage, and garlic. Keeping cavity fillings in place, carefully place squash, cut side down, on prepared baking sheet. Bake in preheated oven until squash is tender when pierced with a fork, 30 to 35 minutes. Let cool 5 minutes. Discard thyme, sage, and garlic. Cut each squash half in half lengthwise; serve hot.