Preheat your oven to 180C / 350F / Gas mark 4 and line an 8x8 inch square tin with baking parchment, then place to one side.
In a medium sized microwavable bowl melt the butter for 60 seconds on high in the microwave.
Once melted add in the peanut butter, sugar, mashed banana, egg and vanilla extract and mix everything together until it is fully combined.
Pour in the flour, salt, baking powder and ground cinamon and gently fold in the dry ingredients.
Fold in 90% of your candies into the batter.
Pour the batter into your prepared pan and smooth it out on top so it fills every corner. Sprinkle the remaining candies over the top ad place it in your hot oven.
Bake for 23-27 minutes.
I have a pretty slow oven so it took 27 minutes for mine to be fully baked through. So its a good idea to check it at around the 23 minute mark.
Once baked take the blondie out of your oven and allow it to fully cool down in its tin before you take it out.
Slice into 9, 12 or 25 depending on what sixe blondies you want.
Its best to keep these blondies in a tin in the fridge they are nice cold but if you prefer allow them to come back to room tempreture before serving.
Eat within 3 to 4 days.