Add vanilla bean paste and eggs and mix 10 seconds / speed 4
Add flour and salt and mix 1 minute / speed 4 (it is important you mix for the full minute)
Add prunes and chocolate buttons and mix 20 seconds / reverse / speed 1
Pour mixture into tin and spread to the corners
Bake for 25 minutes and then check … when you touch it with your finger in the middle it should still be soft, but if it is very soft bake for a further 2-3 minutes
Remove from oven and allow to rest in the baking tin until cool
Dust with cacao powder before cutting into squares