Heat your oven to 350°F and lightly grease a 9x13-inch baking dish.
In a medium bowl, whip the butter and sugar together until light. Whisk in the eggs, followed by the vitamin-rich fresh orange zest and orange juice.
Gently fold in the flour and salt until just combined to keep the batter nice and airy. Spread it smoothly into your prepared pan.
Bake for 25 to 30 minutes until the edges are golden and a toothpick inserted in the center comes out clean.
Create a refreshing frosting by beating the cream cheese and butter until smooth, then blending in the remaining orange zest, juice, and powdered sugar.
Poke small holes in the warm bars to let the citrus flavor absorb, spread the light frosting evenly on top, and chill in the fridge before slicing into portion-controlled treats.
Notes
Nutrition per serving: Calories: 224 kcal, Total Carbs: 42g, Net Carbs: 42g, Fats: 6g, Protein: 2g.