Combine the Wet Ingredients- in a large mixing bowl, whisk together the 2 eggs, 1/4 cup coconut or vegetable oil, 1/2 cup brown sugarand 1/4 cup white sugar, 1 teaspoon vanilla, and 1/3 cup sour cream or Greek Yogurt until combined.
Grate the Zucchini- use a box grater/cheese grater to grate the 1 1/2 cups zucchini into the wet ingredients and mix to combine. The zucchini in this recipe does not need to be drained, the moisture from the zucchini helps make this bread soft.
Mix in the Dry Ingredients-add in the 1 1/2 cup all purpose flour, 1 teaspoon baking soda, 1/2 cup cocoa powder, and 1/2 teaspoon salt in with the wet ingredients and mix until well combined.
Add in the Chocolate and Peanut Butter Chips- Fold in the 1/2 cup chocolate chips and 1/2 cup peanut butter chips until well combined throughout the dough.
Bake-spread the zucchini bread batter evenly into a greased 12 inch cast iron skillet. Top with extra chocolate and peanut butter chips and bake for 20-25 minutes in a 350º F oven. Test doneness by inserting a toothpick into the center, if it comes out clean, it is done.