Preheat a fan forced oven to 160C / 325F. Spray the bottom and side of three 8-inch cake tins with oil and line the bottom with baking paper. Set aside.
Add the all-purpose flour, baking powder, bicarb soda, salt and cinnamon to a medium sized mixing bowl and use a whisk to combine. Set aside.
To a separate bowl, add the oil and brown sugar. Mix until well combined. Then add the eggs one at a time, mix well each time. Add the dry ingredients and use a spatula to mix until well combined.
Next, add the walnuts, grated carrots, coconut, orange zest and orange juice and mix until well combined. The mixture will seem thick at first but as you mix it will thin out.
Split between the three 8-inch cake tins and bake for 15-20 minutes or until a toothpick inserted into the center comes out clean.