Preheat your oven to 350°F (175°C).

In a mixing bowl, cream together the softened unsalted butter, powdered sugar, and salt. Gradually add the all-purpose flour until the mixture is crumbly but holds together when pressed.

Line an 8×8-inch baking dish with parchment paper and press the shortbread mixture firmly into the bottom of the dish.

Place the dish in the oven and bake for 15-20 minutes, or until the crust turns a light golden brown.

While the crust is baking, whisk together the mango puree, granulated sugar, eggs, lemon juice, and cornstarch in a separate bowl until smooth.

Once the crust is done baking, remove it from the oven and pour the mango curd mixture over the hot crust, spreading it evenly with a spatula.

Return the baking dish to the oven and bake for an additional 20-25 minutes, or until the mango filling is set and slightly puffed.

Once baked, allow the dessert bars to cool at room temperature. Then refrigerate for at least 2 hours to set.

Once chilled, use the parchment paper to lift the bars out of the dish. Cut into squares, garnish if desired, and serve.