Place a bowl with chopped butter and sugar over a bowl of hot water to melt.
Remove the bowl and use the remaining heat to melt the chopped chocolate.
Add room-temperature eggs and vanilla in two portions, mixing with a whisk each time.
Combine coconut flour, baking powder, cocoa powder, and tapioca starch in another bowl and mix well.
Add the dry mixture to the butter-chocolate bowl in two portions, mixing with a whisk each time.
Heat cacao nibs in a pan for 30 seconds, then mix them into the batter.
Bake in a preheated oven at 180°C for 8-9 minutes at 175°C.
Let cool in the pan, then freeze for 3 hours, cut, and freeze again.