Preheat oven to 160 degrees. Keep a small baking pan ready.
Melt the chocolate and butter in the microwave. Cool slightly.
Beat in the egg, cocoa powder, baking powder, stevia and salt.
In a clean bowl, whisk the egg white till fluffy and stiff. Fold into the chocolate batter. Pour into the pan.
Bake for 15 minutes. Cool slightly. Serve with fruits.