Put on your safety gear then weigh all your ingredients.
Heat your olive oil, lard, and coconut oil over low heat in the double boiler until it reaches 115°F.
While the oils heat, mix together lye and water in a well-ventilated area. Once mixed, let it sit in an ice bath until it reaches 115°F.
When the lye water and oils are at the same temperature, add the oils, then the lye water into the mixing bowl. Use an immersion blender to mix until they reach a light trace.
Add in oatmeal and then blend again.
Add in essential oil, then blend again.
Pour soap into mold. Top the soap with rolled oats and calendula petals. Let sit for 48 hours wrapped in a towel and placed somewhere warm.
After 48 hours, unmold the soap. Cut into equal sections and then let cure for six weeks before use.