The unexpected ingredient you need to add to your brownies
According to Serious Eats, due to the amount of water zucchini contains (around 95%), it can add more moisture and tenderness to your brownies and prevent them from drying out during baking – although it is recommended that you squeeze excess water out of your zucchini before adding it to your batter.
To grate or grate zucchini, you can use a food processor. But, if you don’t want to munch on chunks of zucchini, there are recipes that call for pureeing the vegetable before tossing it into the par-cooked (via King Arthur Baking Company). Be sure to choose a good zucchini when shopping: it should be shiny, firm, and preferably not the biggest. And please use your hands to clean the zucchini before using, not a sponge or brush.
Many zucchini brownie recipes include standard dessert ingredients (eggs, your choice of flour and sweetener, cocoa and baking powder, and chocolate chunks or chips). Because of zucchini’s mild flavor, it won’t eclipse chocolate as a star, making this squash treat perfect for picky eaters and veggie avoiders of all ages. Still, the resulting moister texture might tempt you to consider zucchini for more of your cooking adventures.