In the bowl of a stand mixer fitted with the dough hook, mix the milk, sugar, and yeast until dissolved.
Add the flour, baking powder, and salt. Knead on low speed until a crumbly and dry texture is achieved.
Incorporate the eggs one at a time, kneading on medium speed until a smooth, homogeneous, and slightly sticky dough forms. If necessary, stop the machine and scrape the bottom of the bowl with a spatula to fully incorporate any flour residue.
With the mixer running, add the butter in small pieces, waiting for each addition to be fully absorbed before adding more. The dough will gradually become silky and elastic.
Knead on medium speed for an additional 3 to 4 minutes to develop the gluten.
Transfer the dough to a lightly oiled (or buttered) bowl. Cover immediately with plastic wrap and place in the refrigerator for a slow fermentation of 12 to 24 hours.
Generously butter a 23 x 33 cm (or equivalent 3 liters) baking dish with non-stick spray or softened butter. Pour 15 cl of maple syrup and spread to evenly coat the bottom. Set aside.
(Alternative: butter and syrup a 23 cm cake pan and a 20 x 10 cm loaf pan.)
In a bowl, mix the brown sugar, cinnamon, and a pinch of salt. Set aside.
Remove the dough from the refrigerator. It should be firm and not sticky. Lightly flour the work surface and roll out the dough. Using a rolling pin, roll it to approximately 30 cm long and 60 cm wide.
Spread the softened butter over the entire surface . Evenly sprinkle the sugar-cinnamon mixture.
Roll the dough starting from the nearest edge, squeezing slightly to avoid air pockets. Work quickly to prevent the butter from softening too much.
Cut the roll of dough in half to obtain two pieces of about 30 cm long. Cut each piece into six 5 cm wide segments.
Place the cinnamon rolls in the prepared dish, spacing them slightly apart.
Cover with plastic wrap and let rise for 30 to 35 minutes, until the rolls have almost doubled in volume.
Bake and cook.
Whip together some Philadelphia cheese with sifted powdered sugar, some vanilla extract.