Preheat the oven to 425 degrees.
Place the squash, 2½ tablespoons olive oil, 1 teaspoon salt, ½ teaspoon black pepper, and the red pepper flakes on a sheet pan, toss, and spread out in one layer. Roast for 25 to 35 minutes, until very tender and starting to brown on the edges, tossing once with a metal spatula during roasting. Set aside.
Meanwhile, heat the butter and 2 tablespoons olive oil in a medium (10-inch) sauté pan. Add the onions and cook over medium to medium-low heat for 12 to 15 minutes, tossing occasionally, until golden brown. Add the vinegar and maple syrup and simmer over medium heat for 4 to 6 minutes, until the liquid is reduced. When the squash is tender, add it to the sauté pan with the onions and mash it lightly with a dinner fork. If the mixture is a little dry, add a few tablespoons of apple cider to moisten. Taste for seasonings and reheat over low heat, if necessary.
To assemble the bruschettas, spread a thick layer of ricotta on each toast and spoon the squash mixture on top. Sprinkle with salt and serve warm.
Copyright 2016, Cooking for Jeffrey, Clarkson Potter/Publishers, All Rights Reserved