Preheat the oven to 180ºC. Grease the baking tin with butter.
In a medium bowl, whisk together the fruit pulp, butter, eggs, sugar, maple syrup and vanilla.
Mix flour, baking powder, salt and cinnamon into a large bowl.
Slowly add the dry ingredients to the wet. Using a rubber spatula, scrape the mixture into the baking tin.
Bake for 30 to 45 minutes or until an inserted skewer comes out clean.
Sprinkle with pistachio nibs. Will last for a week.