In a small saucepan cook prunes and 80 ml prune juice on low heat for 8-10 minutes, or until the liquid has evaporated and about 2 tablespoons are left. Cool.
Pour the prunes and 2 tbs of prune juice into a food processor, add the remaining prune juice (120 ml), olive oil and vanilla extract. Mix until the ingredients are well combined. Set aside.
Whit a hand held mixer whisk the eggs with sugar until frothy, 3-4 minutes.
Mix the ground almonds, cocoa, baking powder and salt in a separate bowl and add to the egg mixture. Stir to combine.
Add the prune mixture and stir until all the ingredients are well combined.
Pour the batter into a 23 x 33 cm baking pan greased with olive oil and bake in a preheated oven at 170°C for 20-25 minutes or until a toothpick comes out clean.