Create a double boiler by bringing a medium pan filled with about an inch of water to a simmer, then turn the heat to as low as it will go. Place a heatproof bowl, that’s just big enough to sit on top, onto the pan and make sure the bottom of the bowl does not touch the water. Put the nut butter and cacao liquor buttons into the bowl. Let the chocolate sit for 1-2 mins to melt slightly, then stir the chocolate every 1-2 mins until it is completely melted with the nut butter. Remove the bowl from the heat.
Healthy chocolate brownies
Heat the oven to 190C/170C fan/gas 5 and line a shallow 23cm square baking tin with baking parchment. Tip the beans, cocoa, coffee granules, xylitol, vanilla, eggs and yogurt into a large bowl. Blitz using a hand blender until smooth. Or, do this in a food processor. Add the baking powder, then blitz again.