In a medium pan, heat vegan butter over medium-low heat until melted. Whisk in flour and let cook for 1-2 minutes. Whisk in non-dairy milk, butternut squash mixture, and any optional seasonings. Continue to whisk until the mixture begins to thicken (about 1-2 minutes). If it's too thick, add in more milk. Once thickened, remove it from the burner. Fold into pasta and serve warm, enjoy!