Dissolve the fresh yeast and sugar in the lukewarm milk.
Melt the butter and let it cool off before adding it to the milk.
Add all-purpose flour and salt. Knead the dough for about 10 minutes or until it assemblies into a nice and smooth dough. You can with advantage use a kitchen machine.
Cover the bowl with a clean dish towel and let the dough rise into double size someplace warm. This takes about 30 minutes.
Flatten the dough into a square with a size of about 40 x 40 cm (16 x 16 inch). Transfer the dough onto a parchment paper covered oven plate. Let the dough rise for another 20 minutes. While the dough is rising prepare the sugar topping.
In a small sauce pan; melt the butter and brown sugar. When the butter-sugar mixture is hot add the heavy cream and mix it together. Remove the mixture from the heat and let it cool off.
Use your fingers to make indents into the dough. The indents should be deep and almost reach the bottom but without breaking through the dough. Also, make a small moat along the edge of the dough to keep the sugar topping on the top.
Distribute the prepared sugar topping across the dough and bake the cake for 12 minutes in a 225 C (440 F) well-preheated oven.
Let the cake cook off a little bit before serving it.