In a separate bowl, beat the egg whites into egg whites
Mix the oat flakes, butter-vanilla flavor, whey and hot water to a cream and allow to cool a little. Then fold the cream into the egg whites, mix everything well. Then carefully fold in the blueberries and pour the mixture into a silicone mold.
Put the mixture in the oven for 40 minutes at top / bottom heat of 120 ° C.
Let the cake cool before eating.
The cake has just under 50 g of protein, just 40 g of carbohydrates and about 5 g of fat.