To make the dough, place the flour, sugar, yeast, and salt in a medium bowl and stir to combine. Set aside.

Gently heat the milk and butter together until just warmed and the butter has melted.

Using an electric mixer with a paddle attachment, pour the warm milk and butter into the mixer bowl along with the egg and seeds from the vanilla bean, then add half of the dry ingredients and gently mix until combined.

Slowly add the remaining dry ingredients and mix until the flour has been fully incorporated and the dough is sticking to the sides of the bowl.

If the dough is really sticky, add more flour, 1 tablespoon at a time, until the dough comes away from the sides of the bowl and starts to form a ball.

Turn the dough onto a floured work surface and knead for about 6 minutes until the dough is firm and elastic.

Alternatively, switch to the dough hook on your stand mixer and knead the dough in the bowl for 4 minutes.

Place the dough in a large bowl, loosely cover with plastic wrap, and place a damp kitchen towel over the bowl.

Put in a warm, dark place and leave the dough to rise for 1½ to 2 hours, until it has doubled in volume.

Meanwhile, prepare the ingredients for the sauce.

Melt the butter, sugar, salt and cinnamon together and pour into the bottom of a greased pan measuring 9 x 13-in. Set aside.

For the filling, mix together the brown sugar and cinnamon and set aside.

Chop the chocolate and set aside.

Once the dough has doubled in volume, remove it from the bowl and smooth out onto a well-floured surface.

Roll out into a large rectangle, roughly 14 x 18-in.

Spread the room temperature butter evenly onto the dough rectangle to within ½ inch of the edge on all sides.

Sprinkle the sugar and cinnamon mixture over the buttered area and then scatter with chunks of chocolate, aiming for even coverage.

Starting with a long edge, carefully roll the dough, tucking it in firmly as you go, until you reach the opposite edge.

Using a serrated knife, cut the “log” in the middle, then into quarters, and then into sixteenths to ensure the rolls are uniform in size.

Place the rolls in the pan with the cinnamon sauce, leaving a ½-in. gap between each one.

Place a damp kitchen towel over the pan and allow the rolls to rise a second time by leaving for 45 minutes in a warm, dark place.

Meanwhile, preheat the oven to 350°F.

Bake the rolls in the preheated oven until they are puffed up and golden brown (about 25 minutes.)

Test by pressing lightly on one of the rolls: if it doesn’t feel soft inside, the rolls are cooked.

Allow to cool for at least 30 minutes in the pan.

Then, using a baking sheet or large plate that will cover the entire pan, very carefully but swiftly invert the pan.

Delicious warm or cold.