Preheat the oven to 350 degrees. Coat a loaf pan with cooking spray.
Combine the flour, sugar, poppy seeds, baking powder, and salt together in a large bowl; whisk until well combined.
In a separate bowl, combine the eggs, vegetable oil, sour cream, milk, lemon juice, lemon zest, and vanilla extract; whisk until well combined.
Add the wet ingredients to the dry ingredients and stir until just combined. Don't overmix.
Pour the mixture into the prepared loaf pan and bake for 40-45 minutes, or until a tester inserted in the middle comes out clean.
Cool in the pan for a few minutes before removing it to finish cooling on a baking rack.
Make the lemon glaze by combining the powder sugar with the lemon juice until creamy and smooth.
Drizzle the glaze over the cooled lemon poppy seed bread then slice and serve. Enjoy.