Preheat oven 400 degrees F. Slice squash in half lengthwise from stem to base. Remove seeds along with membranes and discard using a spoon, being careful not to remove the flesh.
Place halves cut side down on a baking tray and bake for 50 minutes until flesh is tender.
Remove from oven and allow to cool enough to handle, about 30 minutes. Then, remove strands by using a fork to pull on the flesh. Set aside and reserve squash bowls.
Heat a large skillet with oil or water and saute onion until soft, about 4 minutes. Add garlic, bell pepper, and green onions and cook, stirring for 2 minutes.
Add black beans, corn, cumin, cilantro, sea salt, cayenne pepper, stir to combine and cook for 1 minute. Add the squash strands stirring until fully combined.
Fill squash bowls with mixture and top with cashew cheese sauce. If using store-bought vegan cheese, return to oven to melt for 4 minutes. Garnish with chopped cilantro and dive in!