Peel squash with vegetable peeler (this is the only hard part - I promise!). Cut squash in half lengthwise and remove seeds; cut into 1/2 inch half moon and crescent slices.
Mix flour, brown sugar and allspice in medium bowl. Cut in the butter to make crumbs - do not overmix.
Layer 1/2 of the sliced squash in a baking pan, mixing up the various sizes evenly. Original recipe specified an 11x7 inch pan, but I have used 9x13 inch, 8x8 inch or 3 quart square dishes, depending on the size of the squash.
Top squash with 1/2 crumb mixture.
Add remaining squash and sprinkle with remaining crumb mixture.
Top with pecans and drizzle with maple syrup.
Cover with foil and bake 1 hour.
Remove foil; bake until squash is tender, about 10 minutes.