Preheat your oven to 180C/Fan. Line a 2lb loaf pan with baking parchment.
In a large mixing bowl whisk together your flour, chopped chocolate, mixed spice/cinnamon, baking powder, bicarbonate of soda and salt.
In a separate medium sized bowl combine your mashed bananas, eggs, olive oil and vanilla extract.
Pour wet ingredients into dry and fold just until combined.
Pour the mixture into the prepared tin and top with a banana sliced lengthways if you like.
Bake for 50 minutes. If your cake begins to over brown just place a small piece of foil on the top to keep it from over browning.
Insert a toothpick to check when ready. It should come out with just a few dry crumbs and some melted chocolate. The cake should feel spongey when pierced.
Allow the cake to cool until cool enough to handle then slice up and enjoy slightly warm or allow to cool completely.
