Preheat oven to 350 degrees F. Line an 8x8 or 9x9" baking pan with foil, extending the sides of the foil over the edges of the pan. Spray the foil liberally with cooking spray and set aside.

In a large bowl, stir together the butter and sugar until combined. Gradually add in the eggs and stir until just barely combined - do not over mix, as this will lead to tougher brownies. Lastly, stir in the lemon juice, lemon zest, salt and flour until a soft batter forms.

Spread the batter into the prepared pan and smooth out the top. Bake for approx. 22-25 minutes, no more than that, or until the top is set and lightly golden brown. Cool completely.

Once cool, make your glaze. In a small bowl, whisk together the powdered sugar and lemon juice until a spreadable, pourable glaze is achieved. Pour over the bars and smooth out. Top with lemon zest. Let the glaze set, then cut into squares and serve.