In a large stainless steel pot, combine the olive oil, coconut oil, castor oil, and cocoa butter over medium to low heat. Heat until melted and then move off of burner and allow to cool until around 90 degrees Fahrenheit.
Using gloves and goggles, measure lye by pouring it into a zip close bag on a kitchen scale. Set aside and weigh water. Take both outside. Put on a charcoal mask and pour lye into water and stir until it is dissolved. Do not breathe in the fumes. The chemical reaction will end and the fumes will dissipate in a few minutes. Allow to cool to about 90 degrees Fahrenheit.
5.5 ounces water, 3 ounces lye
When both oils and lye water has cooled, pour lye water into the pot of oils and blend with a stick blender on and off until light trace (It begins to thicken. Learn more about trace here.).
Separate the soap into two parts by pouring half into another pot.
To one half, add pumpkin puree and blend. To the other half, add the ground cinnamon and blend. Pour one half of the soap into a prepared mold (lined if necessary). Use a rubber spatula to scrape well. When both halves are thick enough that the second half won't sink when poured onto the first half, pour slowly into the mold and spread evenly with a rubber spatula. You can pour onto a spatula to "break the pour" if necessary (see "How to Layer Soap" above).
1/4 cup pumpkin puree, 1/2 teaspoon ground cinnamon
Cover. Insulate with towels if your home is cool. After 24 hours, remove from mold and cut into bars. If soap is still very soft, leave it in the mold for 12-24 hours and check again. Cure bars in a cool, dry place for 3-6 weeks to harden.