Preheat oven to 400 degrees. On a foil lined baking sheet, place acorn squash halves face down. Roast in oven 30-40 minutes, or until flesh of squash is soft and can be easily pierced with a fork. Let cool, then scoop out squash flesh into a large mixing bowl. Turn down oven to 350 degrees.

In the mixing bowl, add to squash the eggs, heavy cream, melted butter, vanilla, cinnamon, allspice, and salt, mixing thoroughly with a whisk to break up all the chunks of squash into a smooth, even texture. Pour into a baking dish greased with coconut oil or butter. Cook in oven for 30 minutes, or until casserole is turning slightly golden brown on top. Meanwhile, toast pecan pieces in a sauté pan on medium high heat for 4-6 minutes, tossing often and being careful not to burn. Top casserole with toasted pecan pieces and serve.