Whisk in melted butter, then add the egg and mix until combined.

Add flour, baking powder, and a pinch of salt. Mix until a dough forms.

Knead until smooth, then cover and let rest until slightly puffed.

Make the filling by mixing butter, brown sugar, vanilla sugar, and cinnamon into a spreadable paste.

Make the cream topping by mixing cream cheese, sugar, and milk powder until smooth.

Roll dough into a large rectangle on a lightly floured surface.

Spread filling evenly over the dough, leaving a small border along one long edge.

Roll into a tight log and slice into even rounds.

Arrange rolls in a greased baking dish, cover, and let rise until puffy.

Bake at 350°F (175°C) until golden and cooked through.

Spread cream topping over warm rolls and serve.