Preheat the oven to 350°F. Line a 9-inch loaf pan with parchment paper or coat it with nonstick cooking spray.
In a large mixing bowl, beat the softened butter, sour cream, and sugar with a hand mixer or stand mixer until light and fluffy.
Add the eggs one at a time, mixing well after each addition. Stir in the lemon extract.
In a separate bowl, whisk together the flour, salt, baking soda, and baking powder.
Gradually add the dry ingredients to the wet ingredients, mixing just until combined. Fold in the lemon zest.
Pour the batter into the prepared loaf pan and spread it into an even layer.
Bake for 50–60 minutes, or until a toothpick inserted into the center comes out clean.
Let the cake cool in the pan for 10–15 minutes, then transfer it to a wire rack to cool completely.
While the cake cools, whisk together the powdered sugar, milk, and lemon juice until smooth. Add more powdered sugar or milk as needed to reach your desired glaze consistency.
Once the cake has cooled completely, drizzle the glaze evenly over the top.
Slice, serve, and enjoy.
Notes
The lemon Extract is needed for that strong lemon flavor that is similar to the Starbucks cake.