The most extraordinary moist Cinnamon Swirl Zucchini Bread made by preheating oven to 350°F greasing and lining 9×5 loaf pan with parchment mixing 3 tbsp melted butter 1/4 cup brown sugar and 1 tbsp cinnamon for swirl setting aside whisking 2 cups flour 1/2 cup packed brown sugar 1/2 cup granulated sugar 1 tsp baking powder 1/2 tsp baking soda 1/2 tsp salt and 1 1/2 tsp cinnamon whisking 1/2 cup oil 2 room temperature eggs and 1 tsp vanilla adding wet to dry stirring just combined folding in 1 1/2 cups lightly packed shredded zucchini do not squeeze pouring half batter into pan dropping generous spoonfuls of cinnamon swirl over pouring remaining batter over dropping any remaining swirl mixture over top surface using skewer in 3 to 4 gentle S-curve passes to swirl baking 55 to 65 minutes tenting with foil after 40 if browning too fast until toothpick clean cooling 20 minutes in pan lifting onto rack cooling completely whisking 1 cup sifted powdered sugar 2 to 3 tbsp milk and 1/2 tsp vanilla to smooth glaze drizzling over cooled loaf. A completely perfect moist brown sugar cinnamon swirl shredded zucchini vanilla glaze quick bread recipe.