Melt oil in a large pot over medium heat. Add onions and garlic; cook, stirring occasionally, until softened, about 10 minutes. Stir in collards, then baking soda. Stir in coconut cream and coconut milk. Increase heat to medium-high; cook, stirring frequently, until the collards are soft, about 10 minutes.

Puree the mixture in the pot with an immersion blender (or in batches in a regular blender) until smooth (if desired, you can also leave some unpureed for texture). Season with salt and pepper.