Preheat oven to 350 degrees. Grease and flour two standard sized loaf pans and set aside.
In a large bowl, beat oil, eggs, sugar, and vanilla until well combined.
In a separate bowl, combine flour, cinnamon, baking soda, baking powder, and salt and whisk to combine.
Pour the flour mixture into the egg mixture and beat again until fully mixed. Batter will be thick. Add zucchini and beat once more until incorporated.
In a small bowl, combine topping ingredients.
Pour half the batter into prepared pans and sprinkle with 1/2 cinnamon sugar mixture.
Cover with remaining batter and sprinkle with remaining cinnamon and sugar.
Bake at 350 degrees for 45-50 minutes or until a knife is inserted and comes out clean. Allow to cool before slicing.