Preheat the oven to 400°F (200°C). Grease muffin pan, or line with paper liners.
Whisk together flour, poppy seeds, baking powder and salt in a medium bowl. Set aside.
2 cups all-purpose flour, 2 tablespoons poppy seeds, 2 teaspoons baking powder, ¼ teaspoon table salt
In a large mixing bowl with paddle attachment, beat butter and sugar on medium high speed until fluffy, about 3 minutes.
½ cup unsalted butter, ¾ cup granulated sugar
Add the eggs, vanilla extract, lemon juice, and zest. Beat for another 2 minutes, or until nice and fluffy. Scrape the sides of the bowl with a rubber spatula halfway.
2 large eggs, 2 tablespoons lemon juice, 1 teaspoon pure vanilla extract, Zest of one lemon
Add half of the flour mixture and mix until just combined.
Then stir in the milk, followed by the remaining flour mixture. Don’t overmix.
½ cup milk
Divide the batter into 12 muffin cups. The muffin cups will be pretty full, and that's totally ok!
Bake for 15-18 minutes, or until the inserted toothpick comes out clean.
Cool the muffins completely in the muffin pan before taking them out.