Passover Lemon Bars

Name: Passover Lemon Bars
Prep time: 10 min
Cook time: 1 h
Total time: 1 h 10 min
Cuisine: French
Ingredients: 7 tablespoons unsalted melted butter; 2 tablespoons sugar; 1 vanilla bean scraped, or 2 teaspoons extract; ¼ teaspoon kosher or sea salt; ½ cup finely ground almonds; ½ cup matzo cake meal; Zest from 1 lemon (preferably from an organic lemon); 1 cup plus 2 tablespoons sugar; 3 tablespoons potato starch; 3 large eggs; Finely grated zest from 2 lemons, (preferably from organic lemons); ½ cup fresh lemon juice (from about 2 - 3 medium lemons); Pinch of kosher or sea salt; 2 - 3 tablespoons powdered sugar, for dusting (optional)