First prepare a Sacher cake dough according to the classic basic recipe.
To do this, whisk the egg whites with the granulated sugar until foamy.
Whisk in oil, powdered sugar, cocoa, yolks and water. Sift the flour with the baking powder. Mix the flour mixture into the yolk mixture until a smooth dough is formed. Then carefully fold in the beaten egg white.
Line a baking tray with baking paper and spread the cake batter on it. Alternatively, you can use a small round and a slightly larger square baking pan.
Bake at 180 °C for about 1 hour.
Meanwhile, for the cream, whip the whipped cream and puree the strawberries. Mix the strawberries with the curd and gently fold in the whipped cream.
Cut out a square and a circle from the finished cake dough. Cut the circle in half and place one half circle against each square to create a heart shape (see photo). The diameter of the circle should be about the side length of the square.
Spread the resulting heart with the strawberry cream and decorate the cake with colorful sprinkles as desired.