Homemade cashew butter is the best.
Here's my recipe.
I used one 3.5 oz. bar of Trader Joes Organic 73% Cacao Dark Chocolate, which is vegan-friendly.
To melt the chocolate, I broke the bar into pieces, placed in a heatproof ramekin. I filled a small frying pan with about an inch of water and heated the chocolate over medium heat until it melted, stirring frequently.