Preheat oven to 180 degrees C. Grease and flour a 20x30cm baking dish.
In a medium bowl, stir together the flour, mixed spice, baking powder and bicarb soda; set aside. In a large bowl beat the eggs, oil and sugar together until smooth. Stir in the pumpkin then the dry ingredients. Finally, stir in the raisins.
Pour the mixture into the prepared baking pan and spread evenly. Bake for 30 to 40 minutes in the preheated oven. Allow bars to cool before adding the glaze.
To make the glaze, stir together the icing sugar with the maple syrup. If glaze is too thick to drizzle from a spoon, just add a little water. Drizzle over the cooled pumpkin bars before cutting.