Preheat your oven to 350°F. Grease an 8x8-inch baking dish or line it with parchment paper.
In a bowl, mix together the melted butter and sugar.
Beat in the eggs, lemon juice, and lemon extract until combined.
Stir in the flour just until smooth. Don't overmix.
Pour the batter into your prepared pan and spread evenly.
Bake for 20–25 minutes until the edges are lightly golden and a toothpick inserted comes out clean.
(Optional) While they cool, mix powdered sugar and lemon juice to make a glaze. Drizzle over the cooled brownies.