In a large mixing bowl, whisk together the egg whites and sugar until foamy and light in texture, about 2-3 minutes.

Gradually add the almond flour, fresh orange juice, and orange zest to the egg white mixture. Stir until a smooth and cohesive dough forms.

Using your hands, form small balls from the dough about the size of a walnut.

Line a baking sheet with parchment paper, placing the dough balls about 2 inches apart and create an indent in each ball.

Spoon a small amount of orange marmalade into each indent, then place the baking sheet in the refrigerator for 15 minutes.

Preheat your oven to 175°C (356°F).

Remove the chilled cookie dough from the fridge and bake for about 12 minutes, or until the tops are slightly crisp.

Allow the cookies to cool completely on a wire rack and dust lightly with powdered sugar.