Knead yeast and 1 teaspoon sugar until the yeast is liquid. Warm the milk lukewarm. Knead flour, 60 g sugar, salt, yeast mixture, milk and butter to a smooth dough. Cover and leave to rise in a warm place for about 1 hour.
Peel apples, cut the flesh into slices from the core and dice. Heat 60 ml syrup in a pot and stew diced apples for 3-5 minutes.
Roll out the dough rectangularly (approx. 35 x 50 cm) on a floured work surface. Spread apple cubes evenly on top and sprinkle with cinnamon. Roll up the dough sheet from the long side and cut into approx. 12 slices.
Arrange the slices side by side in a greased square springform pan (24 x 24 cm) with the cut surface facing downwards. Cover and leave to rise in a warm place for about 30 minutes. In a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see
manufacturer) bake for about 20 minutes. If necessary, cover with foil shortly before the end of the baking time.
Leave the bacon in a pan and turn it over until crispy. Remove the snails from the oven, let them rest in the mould for a short time and remove them from the mould. Loosen the snails from each other and sprinkle them with some salt flakes.
Break the bacon into pieces and spread them on the snails. Drizzle with remaining syrup.