You cook first because it retards the enzymes that cause spoilage and deterioration.

FREEZING SUMMER AND WINTER SQUASH

Winter squashes all freeze well, but they may lose
their original texture. Summer squash is best suited for
soup after it's been frozen, but freezing is the only way to keep it for any length of time. To freeze pumpkin and
other winter squashes, wash, halve and remove seeds.
Leave squash in halves or peel and cube it. To make a
puree, bake the pumpkin and winter squash halves in a 350
degrees Fahrenheit oven until soft. (Steaming is also
possible but will make a wetter puree). Scrape the meat out
of the shells and mash thoroughly or run through a food
mill. If preparing cubes, peel and steam the cubes until
soft. Leave cubes whole or run a food mill or processor.
Pack into containers. Seal, label and freeze.

To freeze zucchini and other kinds of summer squash,
cut in half, remove seeds, if necessary, and cut into cubes. Steam blanch the cubes for two to three minutes. Drain well and pack the cubes in containers, or mash them or turn them through a food mill before packing. Seal, label and freeze.

If you grate zucchini with the skin on it will stay
crunchy when frozen without blanching. Use the side of the
grater with the largest holes, or use a food processor with
a coarse shredding plate. When you thaw the zucchini, drain
it and save the juice to use in soups and breads. Add
shredded zucchini to quick breads, omelets or spaghetti
sauce or layered in lasagna, where it will provide some
flavor but mainly texture.