You need just 5 ingredients to make the perfect luscious lemon bars. This lemon bar recipe is the perfect balance between sour and sweet. Lemon Bars Ingredients Shortbread Crust 1/2 cup sugar 1 cup salted butter sliced 2 cups flour Lemon Layer 1 1/2 cups sugar 1/4 cup flour 4 large eggs 1 cup lemon juice Instructions Preheat oven to 350 degrees. Line a 9×9 baking pan with parchment paper. In a medium-sized mixing bowl use a pastry cutter to combine the butter, 1/2 cup sugar, and 2 cups flour, or use a food processor. Press this dough into the bottom of the 9×9 pan. Bake for 15 minutes. Five minutes before the crust is done baking, mix together the 1 1/2 cups sugar and 1/4 cup flour. Whisk in the eggs and lemon juice. Gently pour the lemon mixture over the baked crust and return to the oven and bake until lemon layer is set, about 40-50 minutes. Let cool completely before dusting the tops with additional powdered sugar, if desired.