Preheat & Prep: Preheat your oven to 350°F (175°C). Grease two 9x5-inch loaf pans with cooking spray and line them with parchment paper so the bread easily lifts out later; set aside.

Mix Dry Ingredients: In a large mixing bowl, gently stir together the all-purpose flour, baking powder, baking soda, salt, and the dry instant pistachio pudding mix; set aside.

Mix Wet Ingredients: In a separate medium bowl, whisk together the large eggs and granulated sugar until the mixture becomes thick and light lemon in color. Stir in the vanilla extract and vegetable oil until smooth.

Fold in Mix-ins: Add the freshly shredded zucchini (with all its natural juices) and the chopped pistachios to the wet ingredients, stirring just until distributed.

Combine Batters: Pour the wet zucchini mixture into the bowl with the dry flour mixture. Stir together with a rubber spatula until just combined, being careful not to overmix. (Note: The batter will take on a weird green color, but it will bake into a beautiful, natural tone!).

Bake: Divide the heavy batter evenly between the two prepared loaf pans. Bake in the preheated oven for 55 minutes, or until a toothpick inserted in the exact center comes out clean. (Note: The center will most likely sink slightly as it cools, but that is totally okay and expected).

Cool & Serve: Let the loaves cool in the pans for 10 minutes to set up. Carefully remove the loaves from the pans using the parchment paper sling and transfer them to a wire rack to cool completely. Slice each loaf into ten thick slices and serve!