Melt the cacao butter in a double boiler over low heat, stirring occasionally. I simply added the cacao butter to a ceramic bowl and put the bowl into a pan filled with a little hot water. It's important that you turn off the heat once the water in the pan starts simmering, to avoid drops of water getting into the bowl.
Keep stirring until it's completely melted, then add the cashew butter (or coconut butter) and stir to combine.
Finally, sift in the powdered sugar, and also add the vanilla extract, and a pinch of salt.
Prepare two silicone molds and use a spoon to fill the white chocolate mixture into the molds.
Transfer the silicone molds into your fridge for about 1-2 hours (or into your freezer for about 20-30 minutes) until the chocolate firms up.
Remove from the mold and enjoy! Store leftovers in the fridge or freezer.