The mere thought of slicing and dicing a “rock-hard” butternut squash makes your arm throb already. You can slice winter squash easily if you bake it first. Here’s what you should do: Heat oven to 350 degrees farenheit, then pierce the squash all over using a fork. Line a baking sheet with foil, then place the squash and bake for 20 minutes. The process will soften the squash so you can slide a knife easily through its flesh. Remove the seeds and cut it.