Preheat the oven to 400 degrees. While the oven is heating, slice the acorn squash in half lengthwise and clean out the inside of both halves with a spoon.
In a small bowl, melt ¼ cup of unsalted butter and mix in the 4 tablespoons of dark brown sugar. Reserve half of the mixture in a separate bowl and set aside. Using a pastry brush, brush the remaining half of the brown sugar-butter mixture onto both sides of the squash.
Place the squash halves cut side down in a baking dish and bake for 30 minutes. After 30 minutes, remove the dish from the oven. Using tongs, flip each half over to be cut-side up. Brush on the reserved half of the brown sugar-butter mixture. Return to the oven and bake for 15 minutes more.
Meanwhile, place a small pan on the stovetop over medium heat. Melt the 1/4 tbsp of butter and add the 2 tablespoons of pepitas. Cook for about 5 minutes, then remove the pepitas from the pan and place in a small bowl. Immediately toss them with 1/2 teaspoon of cinnamon and 1 teaspoon of brown sugar.
Remove the acorn squash from the oven and place on a serving dish. Serve with the pepitas and spoons!
