Preheat oven to 400 degrees. Add olive oil to a baking dish and add in the acorn squash, tomatoes, onion, and garlic. Drizzle with more olive oil and salt & pepper. Bake for about 40 min.
Meanwhile add the cashews to a bowl and submerge in boiling water.
After 40 min remove the roasted veg from the oven and let cool. Add to a large blender with the basil leaves, vegetable broth, coconut milk, soaked cashews (drain them first), sugar, and additional salt & pepper. The garlic should be soft enough to squeeze the cloves out, then discard the skin. Start on a low speed then gradually turn it up until the soup is extremely smooth. Should only take a minute or 2.
If the soup feels too thick, add more vegetable broth by the 1/4 cup. Since this is a starchy soup, keep in mind it will thicken up some more in the fridge.
Divide into bowls and optionally add a drizzle of coconut milk and salt & pepper on top of each portion.