I always start by combining the flour, sugar, baking powder, baking soda, salt, and poppy seeds in a large bowl. I whisk everything together to make sure the leavening is evenly distributed. This step ensures every muffin rises perfectly.
In another bowl, I whisk together the melted butter, eggs, Greek yogurt, lemon zest, lemon juice, and vanilla extract. Using room temperature eggs helps the mixture stay smooth.
I gently fold the wet ingredients into the dry ingredients until just combined. I’m careful not to overmix; a few lumps are totally fine. This keeps the muffins tender and fluffy.
I scoop the batter evenly into lined muffin tins, filling each about three-quarters full. This prevents overflow and allows the tops to dome nicely.
I bake the muffins at 350°F (175°C) for 20–25 minutes until a toothpick comes out clean. I keep an eye on them because ovens vary, and I love that golden top.
Once baked, I let the muffins cool in the pan for 5 minutes, then transfer them to a cooling rack. If I’m feeling fancy, I drizzle a simple lemon glaze over the tops for an extra citrus punch.