1. On a floured work surface, roll out the dough into a 25-cm (10-inch) by 3-mm (-inch) thick square. Over the entire surface, spread the hazelnut spread or butter for the caramel version. Sprinkle with the nuts or brown sugar and cinnamon for the caramel version. Roll the dough onto itself so as to enclose the filling. Place the cylinder on a baking sheet and freeze for about 1 hour or until the dough is semi-frozen.
2. With the rack in the middle position, preheat the oven to 190 °C (375 °F). Butter 12 muffin cups. Set aside.
3. Slice the dough roll into 12 slices and lay flat in the muffin cups (see note for freezing). Bake for about 18 minutes for the Nutella version and 23 minutes for the caramel version or until golden brown. Let cool for 2 minutes. Unmould by flipping onto parchment paper and let cool completely. Keeps in an airtight container at room temperature for about 1 week.

NOTE FROM RICARDO

Freezing You can freeze the cut slices on a baking sheet lined with parchment paper and then transfer to a sealable freezer plastic bag. Keep them in the freezer until ready to bake.