Preheat your oven to 350°F (175°C) and line a 9x13-inch baking dish with parchment paper.

In a mixing bowl, combine melted unsalted butter, granulated sugar, vanilla extract, all-purpose flour, and a pinch of salt. Mix until a crumbly dough forms.

Press the dough evenly into the bottom of the prepared dish, then prick the surface with a fork to prevent bubbling. Bake for 15-18 minutes, until the edges turn golden brown and the center is firm.

While your crust is cooling, whisk together eggs, granulated sugar, cornstarch, fresh orange juice, grated orange zest, and almond extract in a separate bowl until smooth.

Pour the orange filling over the warm shortbread crust, spreading it evenly with a spatula.

Return the baking dish to the oven and bake the orange bars for 20-22 minutes, or until the filling is set but still jiggles slightly in the center.

After baking, allow the bars to cool at room temperature for about 30 minutes, then chill in the refrigerator for at least 2 hours.

When ready to serve, slice the bars into squares and dust with powdered sugar.