Preheat your oven to 400 degrees F. Line a large rimmed baking sheet with foil for easy cleanup. Cutting acorn squash can be tricky because of the ridged shape. Place each squash on its side, hold it steady, and use a sturdy chef's knife to cut straight down through the center from stem to bottom. Use a spoon to scrape out all the seeds and stringy fibers.

In a small bowl, stir together the melted butter, brown sugar, cinnamon, salt, and pepper until it forms a loose paste. It will look like a slightly grainy mixture and that is exactly right.

Brush or spoon a thin layer of the butter and brown sugar mixture over the cut flesh of each squash half, covering all the ridges and the cavity. Reserve about half of the mixture to add later. Place the squash cut-side down on the prepared baking sheet.

Roast cut-side down for 25 minutes. This position traps steam against the flesh so the squash cooks through evenly and stays moist. At 25 minutes, carefully flip each half cut-side up using tongs. The flesh should feel slightly tender when you press the skin gently with your finger.

Spoon the remaining butter and brown sugar mixture into the cavity of each squash half. Divide the chopped pecans evenly among the cavities, pressing them lightly into the mixture so they stay in place.

Return the pan to the oven and roast for another 15 to 20 minutes. The squash is done when a fork slides into the thickest part of the flesh with no resistance and the edges around the cavity are deep amber and bubbling. The pecans should be toasted and fragrant, not burnt.

Let the squash rest for 5 minutes before serving. Drizzle with a little maple syrup if you want an extra layer of sweetness. Serve each half in its shell so guests can scoop directly from it.