Do not squeeze out the zucchini moisture to keep the brownies moist and fudgy; only lightly pat if extremely watery., Use a plastic knife after cooling to slice brownies neatly without crumbling., Store uncut brownies covered at room temperature for up to 3 days; cut brownies should be wrapped tightly and consumed within 1–2 days for best freshness., These brownies freeze well when wrapped tightly and can be frozen for up to 3 months., For variations, swap different types of chocolate chips, add nuts, espresso powder, cinnamon, or replace some cocoa powder with melted chocolate (reduce oil slightly)., For gluten-free option, replace all-purpose flour with a 1:1 gluten-free flour blend., To make a smaller batch, halve the recipe and bake in an 8×8 pan, checking doneness around 20 minutes.