Preheat the oven to 410°F (210°C). Grease and flour the cake pan. Separate the egg whites from the yolks. In a bowl, mix the egg yolks with the sugar.

Add the salted caramel sauce to the mixture. Stir well. Add the unsweetened cocoa powder and mix thoroughly.

Beat the egg whites until stiff peaks form, then gently fold in the remaining sugar. Gradually fold the egg whites into the batter in several additions.

Pour the batter into the prepared pan and bake for 15 to 20 minutes at 410°F (210°C). The center should remain mousse-like and will finish setting outside the oven.

Your mousse cake is ready! Dust with powdered sugar or unsweetened cocoa powder for extra flavor, or decorate with chocolate shavings for an Easter nest look.