Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper for easy cleanup.

Carefully wash and dry the acorn squash. Place a squash on a cutting board. Using a large, sharp chef's knife, cut the squash in half lengthwise from stem to tip. Use a large spoon to scoop out the seeds and stringy pulp from the center of each half.

Using a paring knife, lightly score the flesh of each squash half in a crosshatch pattern, about 1/4-inch deep. This helps the glaze penetrate the squash. Place the squash halves cut-side up on the prepared baking sheet.

In a small bowl, whisk together the melted butter, maple syrup, brown sugar, cinnamon, nutmeg, salt, and black pepper until the sugar is mostly dissolved.

Using a pastry brush, generously brush about half of the maple-butter glaze all over the cut surfaces and inside the cavity of the squash halves.

Roast for 30 minutes. Remove the baking sheet from the oven and carefully brush the squash with the remaining glaze. The glaze may have solidified slightly; if so, gently warm it for a few seconds in the microwave.

Return the squash to the oven and continue to roast for another 15-20 minutes, or until the squash is tender enough to be easily pierced with a fork and the edges are caramelized. Total roasting time will be about 45-50 minutes.

Remove from the oven, let cool for a few minutes, then sprinkle with toasted pecans before serving.