Preheat your oven to 350°F (175°C). In a medium bowl, combine melted butter and granulated sugar, mixing until well blended. Gradually add all-purpose flour, stirring until the mixture forms a crumbly dough. Press this mixture evenly into the bottom of a greased 9x9-inch baking pan to create a solid crust.

Once your crust is formed, place it in the preheated oven and bake for 15 minutes, or until it turns lightly golden.

In a large mixing bowl, whisk together the eggs, granulated sugar, fresh lemon juice, lemon zest, and finely chopped dried hibiscus flowers until fully combined.

Carefully pour the filling over the crust in the baking pan, ensuring an even distribution. Return the pan to the oven and bake for an additional 30 minutes, or until the filling is set and no longer jiggles.

Remove the pan from the oven and allow the Hibiscus Lemon Bars to cool in the pan on a wire rack. Once cooled to room temperature, transfer them to the refrigerator for at least two hours to firm up before cutting into bars.

Take the chilled Hibiscus Lemon Bars out of the refrigerator. Dust the top with powdered sugar and slice them into squares.