Preheat oven to 325 degrees F (165 degrees C). Prepare two loaf pans with cooking spray.
Mix the eggs, vegetable oil, sugar, zucchini, and vanilla extract together in a large bowl; add the raisins. In a separate bowl, combine the flour, baking soda, baking powder, salt, and 1 teaspoon cinnamon. Whisk the flour mixture into the zucchini mixture, stirring until almost all the lumps are gone. Divide the batter between the two prepared loaf pans.
Whisk the flour mixture into the zucchini mixture, stirring until almost all the lumps are gone. Divide the batter between the two prepared loaf pans, and sprinkle the tops with the brown sugar-cinnamon mixture.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 1 hour. Cool in the pans for 10 minutes before removing to cool completely on a wire rack.
