Preheat the oven to 190 degrees Celsius.
In a mixing bowl, mix the dry ingredients for the muffin mixture (flour, protein powder, bicarbonate of soda, baking powder and cinnamon.
Create a well and add the egg whites, apple puree and greek yogurt.
Combine ingredients until smooth and stir in the milk.
Add in the carrots mixing well.
Divide the mixture between 6 muffin cases in a muffin tin or silicon mold.
Bake in the oven for 20-30 minutes. Muffins will rise and develop a golden colour. Knife should come out clean when cooked.
Allow to cool on a wire tray.
To make the icing, mix the greek yogurt, extra light cream cheese and protein powder.
Ice the buns and dust with cinnamon.
Store in a cool place in an airtight container.