Preheat the oven to 375°F. Lightly coat a 9x13-inch baking dish with nonstick cooking spray.
Place the butternut squash in a large pot. Add enough water to cover the squash.
Bring the water to a boil over medium-high heat. Reduce the heat to a simmer.
Cook for 12 to 15 minutes, or until the squash is very tender.
Using a colander, drain the squash and discard the water.
Return the squash to the pot. Mash the squash until mostly smooth, leaving a little texture.
Add the olive oil, Greek yogurt, eggs, Parmesan cheese, garlic powder, sage, onion powder, salt, and black pepper. Stir until evenly blended.
Spread the squash mixture evenly in the prepared baking dish.
Add the pecans, breadcrumbs, Parmesan cheese, olive oil, and thyme to a small bowl. Stir the topping until evenly mixed.
Sprinkle the topping evenly over the squash.
Bake uncovered for 30 to 35 minutes, or until heated through and lightly browned on top.
Let the casserole stand for 5 minutes before serving.
Notes
Estimated WW Points: 6Check points in the official WW app.
Tips and Tricks
Drain the squash thoroughly - Extra water can make the casserole loose, so let the cooked squash drain well before mashing.Don't make the squash completely smooth - Leaving a little texture keeps the casserole from feeling too much like a puree.Watch the topping near the end - Pecans can brown quickly once they start to toast.Prepare it ahead - Assemble the squash mixture in the baking dish, cover, and refrigerate. Add the topping shortly before baking so it stays crisp.
Storing and Reheating
Refrigerator - Cover leftovers and refrigerate for up to 4 days.Oven - Cover loosely with foil and reheat at 350°F until warmed through. Remove the foil for the last few minutes if the topping needs to crisp again.Microwave - Reheat individual servings in short intervals until hot. The topping will be softer than when reheated in the oven.