Chop each of the acorn squash in half. Use a spoon to scrape out the strings and seeds. Then cut the squash into quarters.
Line a baking sheet with parchment paper. Place the squash on the sheet and drizzle with olive oil on the cut sides, then sprinkle with kosher salt and pepper. Turn cut side down on the sheet and 20 minutes. Remove from the oven and tip the squash to the other side and roast 15 to 20 minutes more, until fork tender and lightly browned on the cut sides.
Place the butter (sliced into pieces) in a small saucepan over medium heat. Heat for a few minutes until it melts, turns foamy, and then starts to become brown in color and smells nutty. Immediately remove from the heat, transfer to a bowl, and stir in the maple syrup.
To serve, garnish the squash with the brown butter maple drizzle and sprinkle with chopped pecans and sea salt.