Lemon Brownie Bars

Name: Lemon Brownie Bars
Prep time: 15 min
Cook time: 24 min
Total time: 39 min
Cuisine: American
Ingredients: 0.5 cup unsalted butter, melted and slightly cooled (113 g); 1 cup granulated sugar (200 g); 2 large eggs, room temp; 1 tsp vanilla extract; 2 tbsp finely grated lemon zest (from 2–3 lemons); 3 tbsp fresh lemon juice; 1 cup all-purpose flour (125 g); 1 tbsp cornstarch; 0.5 tsp fine sea salt; 1.5 cups powdered sugar (180 g); 2–3 tbsp fresh lemon juice, plus extra as needed; extra lemon zest, for topping