Step 1

Preheat the oven to 375F Grease and flour a muffin pan, or use muffin liners.

Step 2

Crack the egg into a large mixing bowl and whisk in the oil, sugar, buttermilk, and vanilla. Beat well until everything is combined.

Step 3

Whisk in the baking powder, baking soda, and salt. Then fold in the flour, followed by the zucchini and blueberries. Fold gently so you don't squish the berries.

Step 4

I like to let the batter rest on the counter for up to an hour for best rising. But this is optional, you can bake right away if you like. Scoop the batter into prepared muffin cups, filling to the brim. I made 8 muffins, but this will depend on the size of your muffin cups.

Step 5

Bake in your preheated oven for about 25-27 minutes, or until risen and just turning golden, you can check with a toothpick. Different ovens vary greatly, so check these on the early side. If your muffins are smaller than mine, they will take less time.

Step 6

Let the muffins cool for about 15 minutes before loosening the edges and turning them out of the pan to cool completely on a rack before glazing.

Step 7

Whisk the lemon juice with the powdered sugar to make the glaze. Use enough lemon juice to make it thick but spreadable. Spoon the glaze over the top of the cooled muffins.