Farmhouse Coffee Soap

Brew strong coffee using distilled water, cool it completely, and weigh out exactly the amount of liquid your calculation requires. Freeze or make it slushy before adding the NaOH. Slowly add the NaOH to the coffee. It will get very dark and may smell rather awful at this stage—that's normal.
Mix 5 g kaolin with about 1 tablespoon of your measured recipe oil until completely smooth. Stir that slurry into your melted oils before adding the lye solution.
Add 10–15 g extremely finely ground coffee to the oils and stir it in thoroughly.
Mix 5 g unsweetened cocoa powder with a little measured recipe oil to eliminate lumps, then add it to the main oil pot.
Add the coffee/lye solution to the oils.
Use very short stick-blender pulses alternating with hand stirring. Stop at a thin stable emulsion. Don't wait for obvious trace.
At thin emulsion, pour in your pre-measured fragrance oil and hand-stir it thoroughly. Don't stick-blend unless you absolutely have to.
Brew/freeze coffee → make coffee/lye solution → melt oils → kaolin → ground coffee → cocoa → lye → blend ONLY to thin emulsion → hand-stir Coffee Cake FO → pour*

Optional cream-colored top​

If you want it to look like coffee with cream, there's an easy way to make it prettier without making the process stressful.
Before adding cocoa powder to everything, don't put the cocoa in the main oils. Instead, prepare a 5 g cocoa/oil slurry and hold it.
After reaching emulsion, split off about 15–20% of the batter and leave that portion without cocoa. Hand-stir the cocoa slurry into the remaining 80–85%. Then hand-stir the fragrance into both portions and pour the brown base followed by a loose cream swirl across the top.