01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners or lightly grease each cup.
02 - In a large bowl, whisk together flour, sugar, poppyseeds, baking powder, baking soda, and salt until evenly blended.
03 - In a separate bowl, whisk ricotta cheese, eggs, melted butter, milk, lemon juice, lemon zest, and vanilla extract until smooth.
04 - Pour wet ingredients over dry ingredients and fold together gently using a spatula until just incorporated; avoid overmixing.
05 - Divide batter evenly among muffin cups, filling each about three-quarters full.
06 - Bake for 18 to 22 minutes, or until a toothpick inserted in the center comes out clean and tops are lightly golden.
07 - Remove muffins from oven and allow to cool in the tin for 5 minutes. Transfer to a wire rack to cool completely.