1 Preheat the oven to 200°C (approximately 400°F).
2 For the batter: Separate eggs and beat yolks with half the sugar until frothy. Beat egg whites and salt until stiff, add remaining sugar and continue to beat until mixture is glossy. Fold yolks into whites. Combine flour and cornstarch and fold into egg mixture.
3 Pour batter into a baking sheet lined with parchment paper. Bake for 10-15 minutes. Remove and release onto a sugared tea towel, remove parchment paper and let cool. Cut into 3 equal strips.
For the filling: Combine marzipan, powdered sugar and liqueur. Knead and thinly roll out to the size of the cake, then slice into 3 identical strips. Heat jam, strain through a sieve and brush onto strips of cake. Top each strip with a strip of marzipan. Cover and let set overnight.
4 Cut cakes into small squares or use cookie cutters to cut out shapes.
5 For the topping: Beat egg whites and lemon juice until stiff. Fold in powdered sugar and stir until a thick glaze is formed. Color, as desired, with food coloring.
6 Coarsely chop chocolate and melt over a double boiler. Remove from heat and let cool.
7 Place petit fours put on a cake rack and coat with glaze. Let dry completely, then drizzle with chocolate, decorate with marzipan figures decorate and let dry again.
8 Dip the bottom third of the petit fours in remaining chocolate. Let dry again and serve in paper liners.