4: Continue kneading until the butter is fully mixed in. Gather the dough into a ball, wrap in plastic film and leave to rest for 1 hour at room temperature.
5: After resting, press down on the dough (to expel gas), gather into a ball again, then wrap in plastic film and refrigerate overnight.
7: Melt 30 g clarified butter in a frying pan on high heat, then add 50 g brown sugar.
8: When the sugar begins to caramelize, add the apples all at once and sauté until well cooked and caramelized.
9:
Roll the brioche
Take the brioche dough out of the fridge and dust with flour.
10: Roll out into a strip the same width as the length of your loaf tin or mould, and about 60 cm (2 ft) long.
11: Lay apple pieces in a row at the near end of the strip...
12: ...and start rolling up, adding more rows of apples as you go.
13: Finish by turning the "seam" to underneath. Trim the roll if necessary to fit your tin.
14: Sit the roll in the tin or mould and glaze. Leave in a warm place to rest for 1 hour 30 minutes.
15: After resting, glaze the brioche again. Preheat the oven to 360°F (180°C).
16: If you wish, you can snip the top of the brioche with scisors to help it rise in the oven.
17: Bake for about 30 minutes.
18: Leave to cool on a wire rack.
Remarks
The proportion of chestnut flour may appear small, but this is necessary: any more and the brioche will not rise properly. It is important at step 8 to cook the apples well, otherwise, when rolled into the dough, they will give off steam during baking and create unsightly holes in the brioche.