Preheat oven to 400°F and line muffin tins with paper baking cups.
In a large mixing bowl, whisk together flour, sugar, salt, baking powder, baking soda, and poppyseeds.
In a separate bowl, combine the eggs, yogurt, lemon zest, lemon juice, vanilla extract, and melted butter. Stir into the flour mixture just until the ingredients are incorporated.
Fill muffin cups two-thirds of the way with batter.
Bake for approximately 18-20 minutes, or until a toothpick inserted near the center comes out clean. Cool for 5 minutes before removing from pan to a wire rack.
Serve warm or at room temperature.
Notes
*I like to use either full fat or reduced-fat yogurt for baking. Non-fat yogurt doesn't seem to work too well. *If you don't want to use melted butter, you can substitute with canola oil.