Preheat oven to 350 degrees Fahrenheit (175 degrees Celsius).

Place the butternut squashes, whole, on a baking sheet. Wrap the sweet potato in foil and place on the baking sheet as well. Bake for one hour, or until a fork can very easily pierce the skin of the squash. Let cool.

Meanwhile, heat oil in a large pan and sauté the onions until golden.

Peel the squash and discard the seeds. Discard the peel of the sweet potato as well. Place in a large bowl and purée with a stick blender. Add the spices and eggs and blend until creamy. Add the sautéed onions and mix with a spoon until combined.

Prepare two oven-to-tableware or Pyrex pie pans, or two nine-inch (23-centimeter) rounds, and pour in a thin layer of olive oil to cover the bottoms. Fill both pans with butternut mixture until almost full. Bake for 45 minutes, until the centers are firm.

Preheat oven to 350 degrees Fahrenheit (175 degrees Celsius).

Place margarine, almond flour, sugar, and coconut flour in a bowl and crumble between your fingers to create a crumbly, sand-like consistency. Add oil by tablespoonful and mix between your fingers. Small clumps of crumbs should form. Lay out evenly on a lined baking sheet. You can add the slivered pecans or almonds at this point, if using. Bake for eight to 10 minutes, or until edges just begin to brown. Remove from oven and fluff with a fork to create crumbs. Let cool completely.

You can add the crunchy nut topping to the warm kugel immediately before serving, or rewarm the kugel topped with the nut topping for just a few minutes. Both the kugel and the topping freeze very well.