Step 1: Prepare for Baking:

Preheat your oven to 350°F (175°C). This ensures even baking and prevents the loaf from becoming dry or undercooked. Grease a 9×5-inch loaf pan thoroughly with butter or cooking spray. Then, line the pan with parchment paper, leaving an overhang on the sides. This makes it incredibly easy to lift the loaf out of the pan once it's cooled, preventing it from sticking and ensuring a clean release. The parchment paper also acts as a protective barrier, preventing the bottom and sides of the loaf from becoming overly browned.

Step 2: Mix the Dry Ingredients:

In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt. Whisking is crucial for evenly distributing the leavening agents (baking powder and baking soda) throughout the flour. This ensures a uniform rise and a light, airy texture. Sifting the flour before measuring can also help to prevent lumps and create a more consistent batter. Set the dry ingredients aside for later use.

Step 3: Prepare the Wet Ingredients:

In a large mixing bowl, whisk together the eggs, granulated sugar, sour cream (or Greek yogurt), oil, and melted butter until smooth. The key here is to thoroughly combine the ingredients, ensuring that the sugar is completely dissolved. This helps to create a smooth and even batter. Using room temperature eggs can also improve the emulsion and result in a lighter, fluffier loaf. The melted butter adds richness and moisture to the cake.

Step 4: Infuse with Lemon Flavor:

To the wet ingredients, add the lemon zest, lemon juice, vanilla extract, and lemon extract (if using). The lemon zest is where most of the lemon flavor resides, so don't skimp on it! Use a microplane zester to finely grate the zest, avoiding the bitter white pith. Fresh lemon juice adds a bright tanginess that perfectly complements the sweetness of the sugar. Vanilla extract enhances the overall flavor profile, while lemon extract intensifies the lemony notes.

Step 5: Combine the Mixtures:

Gradually add the dry ingredients to the wet ingredients, stirring gently until just combined. This is the most crucial step in preventing a tough or dense loaf. Overmixing develops the gluten in the flour, resulting in a chewy texture. Stir only until the dry ingredients are just moistened. A few streaks of flour are okay; they will disappear during baking.

Step 6: Bake the Loaf:

Pour the batter into the prepared loaf pan and smooth the top with a spatula. This ensures even baking and prevents the loaf from developing a lopsided appearance. Bake in the preheated oven for 45-50 minutes, or until a toothpick inserted into the center comes out clean. The baking time may vary depending on your oven, so it's important to check for doneness using a toothpick. If the top of the loaf is browning too quickly, you can tent it with foil to prevent it from burning.

Step 7: Cool the Loaf:

Let the loaf cool in the pan for 10 minutes before attempting to remove it. This allows the cake to firm up slightly, making it less likely to break or crumble. After 10 minutes, carefully lift the loaf out of the pan using the parchment paper overhang and transfer it to a wire rack to cool completely. Allow the loaf to cool completely before glazing.

Step 8: Make the Lemon Glaze:

In a small bowl, whisk together the powdered sugar and 2-3 tablespoons of fresh lemon juice until smooth. Start with 2 tablespoons and add more lemon juice as needed to achieve the desired consistency. The glaze should be thick enough to cling to the loaf but thin enough to drizzle easily. If you want to add an extra touch of lemon flavor, you can also incorporate 1/2 teaspoon of lemon zest into the glaze.

Step 9: Glaze and Serve:

Once the loaf is completely cool, drizzle the lemon glaze evenly over the top. Garnish with lemon zest, if desired, for a pop of color and added lemon aroma. Let the glaze set for a few minutes before slicing and serving. The glaze will harden slightly as it sits, creating a beautiful and delicious finishing touch.