Preheat your oven to 350℉. Generously grease a 9x5-inch loaf pan.
In a medium bowl, whisk together the flour, poppy seeds, baking powder, baking soda, and salt.
In a large bowl, combine the sugar, milk, oil, eggs, lemon zest, lemon extract if using, lemon juice, and vanilla. Whisk until blended. Add the dry ingredients to the liquid and whisk just until combined. Don’t overmix.
Scrape the batter into the prepared pan. Bake until a cake tester inserted sideways into the center of the bread comes out clean, 50 to 60 minutes. Let the bread cool on a rack at least 15 minutes before unmolding onto a rack to cool completely. Though I must confess I frequently forget to unmold after 15 minutes and cool it completely in the pan, and nothing bad has ever happened.