Preheat your oven to 375°F.
Wash and grate your carrots into fine pieces using a box grater or a microplane.
Wash one orange and zest it until you have 1 tbsp or 8g of orange zest.
Canned Mandarin Oranges work best for this recipe because they are already peeled. Use two 10oz cans and drain away any of the syrup. I had 300g worth once I did this.
You can also use regular mandarin oranges but they have a "skin" on the outside of each piece that makes them a bit tough. Peel all of your oranges and remove as much of the stringy bits as possbile. Separate the pieces. Removing the translucent "skin" on the outside of each orange piece will give you a softer bite as this can get chewy when baked. Cutting it off with the peel by using a knife is the fastest way to do it.
In a large bowl, mix together the oats, protein powder, and baking powder.
Add in the egg whites, milk, orange juice, 1 tbsp of melted butter, carrots, zest, and orange slices.
Spray a 13"x9" pan with oil and add the oat mixture. You can also line this with parchment for easier clean up.
Mix together the cream cheese, vanilla, and sugar. You can microwave it for a bit to help it soften. Put a few spoonfuls of the cream cheese around your pan and swirl it around as best as you can.
Bake for 35-45 minutes.