Butternut Squash or PUMPKIN SOUFFLE

20 oz frozen Butternut Squash puree, or 2 cups of canned pumpkin puree
Extra-virgin olive oil
kosher salt to taste
ground black pepper to taste
Zest of 1 orange, finely grated
1/2tsp minced fresh rosemary
1 tsp ground cinnamon
2 tbsp unsalted butter, at room temperature, plus more for greasing the soufflé dish
4 eggs, separated
Pinch of cream of tartar
Granulated sugar, for the soufflé dish
Confectioners’ sugar, for dusting

Preheat the oven to 350F. Place the butternut squash puree into a food processor, and add the orange zest, rosemary, cinnamon, and butter and season with salt and pepper. Pulse to combine. Whisk in the egg yolks to cream out the filling. In a separate clean bowl beat the egg whites and cream of tartar to stiff peaks. With a rubber spatula, fold one third of the beaten whites into the squash mixture to lighten it. Then gently fold in the rest. Grease a 2-quart soufflé dish with softened butter, sprinkle with granulated sugar, and pour out any excess. (The butter and sugar will keep the soufflé from sticking to the sides, allowing it to rise evenly.) Spoon the butternut squash mixture into the prepared baking dish and place on a cookie sheet. Bake on the middle oven rack for about 30 minutes. The soufflé is done when it has puffed over the rim, the outside is golden, and the center jiggles slightly. Dust with confectioners’ sugar before serving.