Preheat your oven to 325°F. Line 9 wells of a standard 12-cup muffin tin and set the tin aside.
Place all of the ingredients, in the order listed, in a blender or food processor and blend or process until smooth. The batter will be relatively thin.
Fill the prepared wells of the muffin tin about 3/4 of the way full with the batter, and scatter a few of your chosen mix-ins in each well.
Press the mix-ins down a bit into the batter.
Place in the center of the preheated oven and bake until the top springs back when pressed gently and the muffins are very lightly golden brown, about 20 minutes.
Remove from the oven and allow the muffins to cool in the baking tin for 10 minutes before transferring to a wire rack to cool completely before serving.
The muffin liners will peel off easily once the muffins are cool.
Store in a sealed container at room temperature, or seal tightly and freeze for longer storage.
Notes
How to make your own cashew butter.I usually make my own cashew butter since it is so expensive to buy. Simply place about 1/2 pound (8 ounces) raw cashew pieces (you can use whole cashews, but they’re much more expensive) in a high-speed blender or food processor, along with 1 tablespoon virgin coconut oil or nonhydrogenated vegetable shortening and blend or process until smooth (about 5 to 6 minutes).