Gently warm the milk until just warm to the touch. Combine warm milk with yeast and sugar, letting it sit until frothy.

Add flour and melted butter to the yeast mixture, mixing until a dough forms. Knead on a floured surface until smooth and elastic.

Place kneaded dough in a greased bowl, cover with a damp cloth, and let rise in a warm area for about 3 hours.

Whip cream until soft peaks form. Fold in sugar and cornstarch to make the filling.

Preheat oven to 375°F (190°C). Roll dough into a large rectangle and cut into squares. Fill squares with cream filling and jam, seal edges.

Place shaped buns on a greased baking sheet and rise for an additional 30 minutes.

Bake for about 25-30 minutes until golden brown. Cool on a wire rack before serving.

Optionally, dust with powdered sugar before serving for an elegant touch.