Kardinalschnitte (Cardinal's Slice)

Instructions

1. Preheat the oven to 350°F (175°C). Grease and flour a 9x13 inch baking dish.
2. In a large bowl, beat the egg yolks with 1/2 cup of sugar until light and fluffy. Stir in the vanilla extract.
3. Gently fold in the flour until just combined.
4. In a separate bowl, beat the egg whites until soft peaks form. Gradually add the remaining 1/2 cup of sugar and continue to beat until stiff peaks form.
5. Carefully fold the egg whites into the yolk mixture until no streaks remain. Pour the batter into the prepared baking dish and spread it out evenly.
6. Bake in the preheated oven for 15-20 minutes, or until the cake is golden and springs back when lightly touched.
7. While the cake is baking, prepare the custard filling. In a saucepan, whisk together the milk, cornstarch, and salt. Cook over medium heat, stirring constantly, until the mixture thickens.
8. Remove the custard from the heat and stir in the butter until melted. Let the custard cool to room temperature.
9. Once the cake has cooled, spread the custard evenly over the top.
10. Preheat the broiler. In a clean, dry bowl, beat the egg whites until soft peaks form. Gradually add 1/4 cup of sugar and continue to beat until stiff, glossy peaks form.
11. Spread the meringue over the custard, making sure to seal the edges.
12. Place the cake under the broiler for 2-3 minutes, or until the meringue is golden brown.
13. Let the cake cool before slicing and serving.