Pre-heat oven at 350° F. Line a 9x9 or 8x8 baking pan with aluminum foil with sides of the foil extended over the pan for easy removal of the brownies. Grease aluminum foil with cooking oil or butter.
In a bowl sieve all-purpose flour, baking powder and salt together.
Beat softened butter, granulated sugar, freshly squeezed lemon juice and lemon zest in large bowl. Keep scraping the edges of the bowl while you beat. Beat until butter and sugar is creamy.
Crack 1 egg into the butter mix at a time and beat for 10-15 seconds until incorporated.Tip: do not over mix it will result in tougher brownies. Over mixing will also result in butter and eggs getting separated and the mix will look split.
Finally add flour into the bowl and mix until ingredients are incorporated.
Transfer brownie batter into baking pan lined with aluminum foil.
Bake in pre-heated oven at 350° F for 20 to 22 minutes or until the top of the brownie looks set and is lightly golden brown.Pro-Tip: Do not bake for longer than mentioned time.
Allow brownie to cool for 15 to 20 minutes before you remove and transfer to another tray to add glaze.
While brownie cools make lemon glaze.
For lemon glaze whisk together powdered sugar, lemon zest and start with 1 tablespoon of lemon juice first. Add more lemon juice only if needed to adjust the consistency of glaze. It should be thick but pourable/spreadable consistency.
Once brownies have cooled, carefully lift it off the tray place it on a large plate or tray.
Spread lemon glaze evenly over the brownies.
Allow the glaze to set.
Cut lemon brownies into squares and serve.