Preheat your oven to 180°C (350°F) and line a muffin tin with paper liners.
Zest the lemon to extract about 2 teaspoons of bright, aromatic zest, then juice it until you have about 3 tablespoons of fresh lemon juice.
In a large mixing bowl, whisk together the all-purpose flour, sugar, poppy seeds, and a pinch of salt until evenly combined. This creates a light and airy dry base.
In a separate bowl, beat the eggs until slightly frothy. Add the melted butter or oil, buttermilk, lemon zest, and lemon juice, then whisk until smooth and well combined.
Pour the wet mixture into the bowl with the dry ingredients. Gently fold everything together with a spatula until just combined; a few lumps are okay—overmixing can make the muffins dense.
Divide the batter evenly among the muffin cups, filling each about three-quarters full. Sprinkle a few extra poppy seeds on top if you like a more textured finish.
Bake the muffins in the preheated oven for 20–22 minutes, or until they’re golden brown on top and a toothpick inserted into the center comes out clean.
Remove the muffins from the oven and let them cool in the tin for about 5 minutes to let the crumb set.
Transfer the muffins to a wire rack to cool completely. They should be moist, tender, and bursting with bright lemon scent.
Once cooled, enjoy these muffins warm or at room temperature—perfect for breakfast or a quick snack.
