Preheat the oven to 350F. Lightly spray or butter your 8x8 9r 9x9 baking pan. I like to line it with parchment paper so I can remove the brownies easily for glazing and slicing, but that's optional.
Cream the butter and sugar together in a mixing bowl until light and fluffy.
Blend in the eggs, one at a time.
Mix in the lemon juice and zest. Note: the batter may look curdled at this point, but no worries, that's normal and it will resolve itself when you blend in the flour.
Stir in the salt, and then fold in the flour, stirring just until everything is well incorporated, but don't over mix.
Spread into your prepared pan, evening out the surface with an offset spatula. Bake for 25-30 minutes, or just until set in center. Note: Try not to over bake these, you want that fudgy texture! The surface will not be a 'springy' as a cake is when these brownies are done.
Let the pan cool for about 20 minutes before lifting the brownies out using the parchment paper 'sling' to finish cooling on a rack. If you didn't use parchment, let the brownies cool in the pan on a rack.
Mix the sugar and enough lemon juice to make a thick but pourable glaze. Spread over the top of the completely cooled brownies. Top with a little lemon zest if you like. Let the glaze harden before slicing.