Squash comes in many shapes and sizes, but the most common cooking varieties are butternut, buttercup, acorn and spaghetti. Squash can be simply prepared with a bit of butter, kosher salt and fresh ground pepper. I love to use squash in creamy fall and winter soups or stir it into pasta and risotto. You can also fill acorn squash with your favorite rice for an elegant presentation. Butternut squash and buttercup squash are very similar in flavor and can be used interchangeably.