Heat the olive oil in a large pot or Dutch oven over medium heat. Add the chopped onion and minced garlic, and sauté until the onion is translucent and the garlic is fragrant. Add the diced calabaza squash to the pot and stir to combine with the onions and garlic. Cook for about 5 minutes, stirring occasionally, until the squash starts to soften.
Stir in the ground cumin, ground coriander, and smoked paprika. Cook for another minute to toast the spices and enhance their flavors. Pour in the vegetable broth, making sure the squash is mostly covered. Bring the mixture to a boil, then reduce the heat to low and let it simmer for about 20-25 minutes or until the squash is tender and easily mashed with a fork.
Remove the pot from the heat and use an immersion blender or regular blender to puree the soup until smooth and creamy.
Return the pot to the stove over low heat and stir in the coconut milk. Heat the soup gently, but do not let it boil.
Taste the soup and season with salt and pepper according to your preference. Ladle the calabaza soup into bowls. If desired, garnish with chopped cilantro, toasted pumpkin seeds, or a drizzle of coconut milk for extra flavor and presentation.
Serve the soup hot and enjoy its comforting and velvety texture!