Grind the oats finely to make oat flour.
Whisk the egg whites until they form stiff peaks to make meringue.
Add stevia, non-fat yogurt, and oat flour to the meringue and mix well.
Sift in the low-fat cocoa powder and blend until smooth.
Pour the batter into a pan and bake in a preheated oven at 180°C for 15 minutes.
Slice the strawberries thinly and top the cooled cake with them.