1. Preheat the Oven

Preheat your oven to 350°F (175°C). Grease and flour a 9×5-inch loaf pan or line it with parchment paper for easy removal.

2. Combine Dry Ingredients

In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.

3. Cream Butter and Sugar

In a large mixing bowl, beat the softened butter and granulated sugar together until light and fluffy, about 3-4 minutes. This step is crucial for a light texture.

4. Add Eggs and Flavorings

Add the eggs, one at a time, mixing well after each addition. Then, stir in the lemon zest, lemon juice, and vanilla extract until fully combined.

5. Mix in Dry Ingredients

Gradually add the dry ingredients to the wet mixture, alternating with the buttermilk. Begin and end with the dry ingredients, mixing just until combined. Do not overmix. Gently fold in the poppy seeds.

6. Bake the Cake

Pour the batter into the prepared loaf pan and smooth the top with a spatula. Bake for 50-60 minutes, or until a toothpick inserted into the center comes out clean. If the top starts to brown too quickly, cover it loosely with aluminum foil.

7. Cool the Cake

Once baked, remove the cake from the oven and let it cool in the pan for about 10 minutes. Then, transfer it to a wire rack to cool completely.

8. Prepare the Glaze

While the cake is cooling, prepare the glaze. In a small bowl, whisk together the powdered sugar, lemon juice, and lemon zest until smooth. Adjust the consistency by adding more lemon juice or powdered sugar as needed.

9. Glaze the Cake

Once the loaf cake is completely cool, drizzle the glaze over the top, allowing it to drip down the sides. Let the glaze set for a few minutes before slicing.