Preheat your oven to 350 degrees Fahrenheit. Line an 8 x 8 x 2-inch pan with parchment paper and lightly spray it with nonstick cooking spray. Set it aside.

In a small bowl, add ¾ cup of all-purpose flour, ¼ teaspoon baking powder, and ¼ teaspoon salt. Whisk them together well.

In another small bowl, mix ¾ cup granulated sugar with 2 teaspoons of lemon zest to release its oils.

In a large bowl, combine the melted butter, vegetable oil, and lemon sugar. Beat until well combined.

Add in the two large eggs and 1 tablespoon fresh lemon juice. Mix until fully incorporated.

Gradually add the flour mixture to the wet mixture, stirring until just combined.

Pour the brownie batter into your prepared pan and bake for about 18-20 minutes. Check if they are done with a toothpick; it should come out with a few crumbs.

Once baked, let them cool completely in the pan.

Whisk together ½ cup powdered sugar, 1 tablespoon fresh lemon juice, and 2 teaspoons lemon zest in a small bowl until smooth.

Spread the glaze evenly over the cooled brownies using a spoon or an offset spatula.