In a medium-size saucepan (1 or 2 quart) on low heat, add peanut butter, coconut oil, and cacao powder. Whisk until peanut butter and coconut oil melt and mixture is smooth.
Remove saucepan from the heat and whisk in honey and vanilla. Whisk until completely incorporated.
Stir in the oats and refrigerate for 30 minutes. I put the lid on the saucepan and sit put the pan on a hot pad in the refrigerator. You can transfer the mixture to a plastic bowl with a lid if you prefer.
After 30 minutes, form balls out of the mixture using a spring-release scoop. Gently press the top to flatten them into a cookie shape. You can make them as large or small as you want. My spring release scoop was held approximately 1.5 tablespoons of mixture.
Refrigerate another hour for the cookies to set.
I store these cookies in the refrigerator in an airtight container. If your house is hot, I recommend storing them in the refrigerator so that the coconut oil stays firm and the cookies don't spread.