Preheat oven to 425 degrees Fahrenheit. Line a baking tray with foil or baking paper.
Cut the pumpkin into 1 to 2-inch sized pieces and coat in olive oil. Bake for about 20-30 minutes or until soft and lightly caramelized.
Transfer pumpkin to a food processor. Add tahini, lemon juice, garlic, salt, and chili powder. Process the mixture until smooth. If the paste is too thick add 1-2 tablespoon water to thin it out.
Transfer the hummus onto a plate and smooth it with the back of a spoon. Using a large knife with the wide tip, press down into the hummus to make the "eyes" and draw a line for the "mouth". Drizzle with olive oil or chili oil and sprinkle with sesame seeds and cilantro. Add pine nuts, sunflower or pumpkin seeds for the "teeth".
You can use butternut squash instead of pumpkin.
The smaller you cut the pumpkin, the less time it needs to cook.