In a microwave safe mug, mix together the dry ingredients - flour, cocoa powder, baking powder, baking soda , cinnamon powder and sugar, mix everything well.
Add the prunes puree and vanilla extract to the mug, mix everything well until the batter is well combines. Sometimes flour may stick to the bottom of the mug, so just make sure to mix everything using a spoon, to avoid the flour sticking to the bottom of the mug.
Microwave in high for 3 minutes, allow the cake to cool down, enjoy!