Lemon Bar White Chocolate Brownies

Name: Lemon Bar White Chocolate Brownies
Prep time: 2 h 30 min
Cook time: 40 min
Total time: 3 h 10 min
Cuisine: American
Ingredients: 3/4 cup salted butter; 6 ounces white chocolate (chopped (see note)); 1 1/2 cups granulated sugar; 2 large eggs; 2 teaspoons vanilla extract; 1 to 2 teaspoons fresh lemon zest; 2 1/2 cups all-purpose flour; 1/4 teaspoon salt; 1/2 teaspoon baking powder; 4 large eggs; 1 1/3 cups granulated sugar; 1 teaspoon fresh lemon zest; 2/3 cup fresh lemon juice (from about 4-5 lemons); 1/4 cup all-purpose flour; Powdered sugar (for dusting)