Preparation and total preparation time about 40 min, marinating: about half an hour, baking: about five minutes.
Preparation coffee plums: Marinate in cognac for thirty minutes.
Boil water with sugar, vanilla stalks and seeds, reduce temperature, boil for about ten minutes to a syrup on low heat. Add espresso, boil, reduce temperature, add marinated plums, simmer in broth for about ten minutes on low heat, cool, put aside with lid closed.
Stars: unfold dough sheets, fold 2 dough sheets 1 time each to make two four-layer doughs. Cut out different sized stars from the strudel dough and place on two baking sheets lined with parchment paper. Bring water with sugar to a boil without stirring, reduce temperature, and gently bubble, swirling the skillet occasionally, until a light brown caramel forms. Remove skillet from heat, add water, and briefly bubble gently with lid closed until caramel is dissolved. Add butter, stirring until melted. Coat the stars with the caramel butter on the spot. Bake: about five minutes in the middle of the oven heated to 180 degrees. Remove, cool on a rack.
Serve: Form balls with the ice cream scoop, spread evenly with the plums on plates, decorate with the stars.
Note: Use a heat-resistant plastic brush for the caramel butter.