How to cook Spaghetti Squash - A low carb pasta replacement! Spaghetti squash is an easy to prepare, low carb, and delicious pasta replacement! I was reluctant to try this for a long time as I normally do not like these kinds of veggies. I am glad that I tried it because it turned out very good! Note: You do not want to over cook this because it will turn out mushy. I cooked this one for 45 minutes and the outside was nice and noodly but the inside was mushy. I cooked another one today for 40 minutes and it was perfectly noodly all the way through.