Preheat the oven to 175°C / 350°F and lightly grease a 9x9 inch baking dish.
Blend the cottage cheese, eggs, egg whites, oat flour, baking powder, vanilla, spices, salt and sweetener until smooth.
Fold through the grated carrot by hand.
Spread evenly into the baking dish and bake for 28 to 35 minutes, checking from around 25 minutes.
Let the cake cool completely.
Mix all of the frosting ingredients until smooth and sweeten to taste.
Spread the frosting over the cooled cake and cut into 9 large squares.
