Heat the olive oil and butter over medium-low heat in a large non-stick skillet.
Add the garlic and sage and saute until very fragrant, about 2 to 3 minutes. Add the prosciutto, lemon zest, lemon juice, and butternut squash noodles. Saute, stirring occasionally, until butternut squash noodles are soft, but still al dente, about 12 to 15 minutes. Note: if you are having a difficult time getting your noodles to soften up, cover the skillet for a few minutes to allow the noodles to steam.