Cut the soap base into cubes with a kitchen knife. Place them into a large microwave-safe and heatproof jug.
Melt them in the microwave for about 20-30 seconds. The double boiler works great as well. Stir well after this first session and melt again for 30 seconds. Remember to stir well after each microwave session.
Once completely melted, stir in 1 tablespoon of pumpkin seed oil, vitamin E oil, pumpkin pie spice (optional), 15 drops of pumpkin pie essential oil, and colorant (if using).
Pour the melted soap into the mold and allow it to cool. You can place it in the fridge for 30 minutes or until hard to the touch.