Ingredients

• 3/4 cup unsalted butter, melted
• 1/2 cup white sugar
• 1/2 cup firmly packed light brown sugar
• 3/4 teaspoon salt
• 2 teaspoons vanilla extract
• 2 cups all-purpose flour
• 1/4 teaspoon baking powder
• 3 large eggs, at room temperature, divided
• 1 cup plus 2 tablespoons white sugar
• 2 tablespoons cornstarch
• 2 tablespoons freshly grated lemon zest
• 1 pinch salt
• 3 tablespoons unsalted butter, melted and cooled
• 1/2 cup freshly squeezed lemon juice