Step 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.

Step 2: Prepare the Batter

1. In a large mixing bowl, cream together the butter and sugar with an electric mixer until light and fluffy (about 3-4 minutes).
2. Add eggs one at a time, beating well after each addition.
3. Mix in the lemon zest, lemon juice, vanilla extract, and sour cream until combined.

Step 3: Mix the Dry Ingredients

• In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.

Step 4: Combine Wet and Dry Ingredients

1. Gradually add the dry ingredients to the butter mixture, mixing on low speed until just combined.
2. Gently fold in the blueberries that have been tossed in flour, taking care not to overmix as this can crush the berries.

Step 5: Bake the Cake

• Pour the batter into the prepared loaf pan, spreading it evenly. Bake for 50-60 minutes, or until a toothpick inserted into the center comes out clean. If the top begins to brown too quickly, tent with aluminum foil halfway through baking.

Step 6: Prepare the Lemon Glaze

• While the cake cools, whisk together the powdered sugar, lemon juice, and optional lemon zest until smooth and pourable. Adjust the consistency with more lemon juice if needed.

Step 7: Glaze the Cake

• Once the cake is fully cooled, remove it from the pan. Drizzle the lemon glaze over the top of the cake, letting it run down the sides for an elegant look.