Preheat oven to 350°F and line a baking sheet with parchment paper.
Separate the eggs. Beat the egg whites with a pinch of salt until stiff. Then, gradually add the sugar. Now, stir in the egg yolks one at a time.
In a separate bowl, combine the flour and cornstarch. Sift this mixture over the egg mixture and gently fold to combine.
Spread the batter evenly on the baking sheet and bake for about 12-15 minutes, until golden brown. Let it cool completely.
For the sour cream layer, combine the milk, sugar, and instant pudding mix in a saucepan and bring to a boil, stirring constantly until the mixture thickens into a pudding.
Once the cream has properly cooled, stir in the sour cream. Then spread the cream evenly over the sponge cake base.
Drain the cherries well, but hang on to the cherry juice and set aside. Prepare a cherry gelatin glaze according to package instructions using cherry juice and water.
Refrigerate the cake for at least 2 hours to allow the glaze to set firmly.
