Drain and rinse cashews and add to blender along with just boiled water, pumpkin puree, mustard, lime juice, chili powder, chipotle powder, nutritional yeast, hot sauce, and sea salt.
Blend on high for a minute or two, until very smooth and creamy. If the mixture is too thick to blend, add more boiling water a little at a time until it blends smoothly, but is still quite thick.