Preheat oven to 425 degrees F. Line 2 muffin tins with about 20 paper liners. Set aside. Meanwhile, in a large bowl, whisk together the flour, baking powder, and salt.

Stir in the lemon zest, oil, sugar, eggs, buttermilk, lemon juice, and vanilla extract until a soft but lumpy batter has formed. Gently fold in the poppyseeds. Do NOT over mix the batter - it should remain pretty lumpy throughout, as overmixing results in tough, dry muffins.

Drop two heaping Tablespoonfuls of batter evenly among the muffin cups, filling about 3/4 full. Bake for 5 minutes at 425, then reduce the oven temperature to 375 degrees F. for 15-20 minutes or until a toothpick inserted near the center comes out clean or with moist crumbs. Cool for about 10 minutes before serving. Serve warm or at room temperature. Store muffins covered, airtight.