1cuppacked grated zucchinimake sure to use a cheesecloth or paper towels to wring all the liquid from the zucchini, about 1 zucchini or 6 mini zucchinis
Preheat the oven to 350 degrees F.
Line a 12-cup muffin pan with paper liners.
Use a microplane to grate the zest off the lemon or if you don’t have a fine grater, use a vegetable peeler to remove the zest from the lemon in wide strips, being careful not to remove the white pith.
Combine the lemon zest and sugar in a food processor and process until the zest is finely chopped and well mixed with the sugar.
Stir in the poppy seeds. Scoop out 3 tablespoons of the lemon sugar mixture and set aside.
Whisk the flour, baking soda, baking powder and salt in a large bowl.
In a medium bowl, whisk the remaining lemon sugar mixture, the vegetable oil, buttermilk, vanilla and eggs; stir into the flour mixture until just combined. Stir in the zucchini.
Divide the batter among the muffin cups, filling them three-quarters of the way.
Tap the bottom of the pan lightly on the counter to smooth out the batter.
Sprinkle the tops of the muffins with the reserved lemon sugar mixture.
Bake until the muffins are golden brown around the edges and a toothpick inserted into the center comes out clean, 23 to 25 minutes.
Let the muffins cool 5 minutes in the pan, then remove to a rack to cool completely.