Step 1: Preheat your oven to 350°F (175°C) to ensure even baking.
Step 2: Grease your loaf pan with butter or line it with parchment paper.
Step 3: In a mixing bowl, cream together the softened butter and granulated sugar until light and fluffy, about 3-4 minutes.
Step 4: Add the sour cream, vanilla extract, lemon extract, eggs, lemon zest, and lemon juice to the mixture. Mix until well combined.
Step 5: In a separate bowl, whisk together the all-purpose flour, baking soda, baking powder, and salt.
Step 6: Gradually add the dry mixture to the wet ingredients, stirring gently until just combined.
Step 7: Pour the batter into the prepared loaf pan, smoothing the top with a rubber spatula.
Step 8: Bake for 55-60 minutes, or until a toothpick inserted into the center comes out clean.
Step 9: Allow the loaf to cool in the pan for about 10 minutes before transferring it to a cooling rack.
Step 10: While the loaf cools, whisk together the powdered sugar, milk, lemon juice, lemon extract, and optional salt until smooth.
Step 11: Drizzle the icing generously over the cooled loaf and let it set before slicing.