Polish Cake Recipe - Pani Walewska

Name: Polish Cake Recipe - Pani Walewska
Prep time: 1 h
Cook time: 1 h
Total time: 1 h 30 min
Ingredients: 4 egg yolks; 3/4 cup granulated sugar; 1/2 tsp salt; 1 cup butter, unsalted, room temperature; 1/4 cup sour cream; 1 tsp vanilla extract; 1.5 tsp baking powder; 1 tsp baking soda; 3 cups all-purpose flour; 4 egg whites; 1 cup sugar, granulated; 1/8 salt; 2 tbsp heavy whipping cream, boiling hot; 2 tbsp dark chocolate chips; 2 cups plum butter (tart); 1 cup chopped walnuts or slivered/sliced almonds; 1 cup raspberries (optional); 6 egg yolks; 3/4 cup sugar, granulated; 3 cups whole milk; 2 tsp vanilla extract; 5 tbsp all-purpose flour; 4 oz butter, unsalted, room temperature; Large Round Piping Tip; Piping Bag; 10-inch round parchment paper circle; 10-inch round baking pan with removable bottom