Preheat the oven to 350 degrees and grease a loaf pan with nonstick cooking spray.

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

In a separate bowl, beat together the butter and sugar until light and fluffy.

Add the eggs, one at a time, beating between each addition.

Add the lemon extract, lemon zest, lemon juice, and sour cream. Beat to mix.

Mix the dry ingredients into the batter until just combined.

Spread the batter into the loaf pan and bake in the preheated oven for 1 hour, until a toothpick inserted into the center comes out clean.

Allow the loaf to cool completely in the pan, then remove and prepare the glaze by whisking the powdered sugar and lemon juice together until smooth. Spread the glaze over the top of the loaf and allow to set and harden before slicing.