Shred the zucchini: Use the large holes of a box grater. Pile the shreds into a clean kitchen towel and squeeze out excess liquid. You want the zucchini damp, not dripping.

Mix dry ingredients: In a large bowl, whisk 2 cups flour, 3/4 cup sugar, 2 teaspoons baking powder, 1/2 teaspoon baking soda, 1/2 teaspoon salt, and 1 teaspoon cinnamon. If using whole wheat flour, sub in up to 3/4 cup for part of the all-purpose.

Whisk wet ingredients: In a separate bowl or large measuring cup, whisk 2 eggs, 1/2 cup oil, 1/2 cup Greek yogurt, and 2 teaspoons vanilla. Add 1 teaspoon lemon zest if using.

Combine: Pour wet ingredients into the dry. Stir gently until you just see a few dry streaks. Do not overmix.

Fold in zucchini: Add the squeezed zucchini and fold until evenly distributed.

Prep blueberries: Toss 1 1/2 cups blueberries with 1 tablespoon flour. This helps prevent sinking and streaking, especially with frozen berries. Fold them into the batter gently.

Portion the batter: Divide evenly among the muffin cups. The cups should be nearly full for a nice dome. Sprinkle tops with turbinado sugar if you like a crisp lid.

Bake: Bake 18–22 minutes, until the tops are golden and a toothpick comes out with a few moist crumbs. If using frozen berries, add 1–2 minutes to the bake time.

Cool: Let muffins rest in the pan for 5 minutes, then transfer to a rack to cool. They continue to set as they cool, so give them a bit of time before eating.