Step 1

Preheat oven to 325°F. Line a large baking sheet with parchment paper.

Step 2

: Put flour, powdered sugar, baking powder, salt and butter in the bowl of a food processor and mix until you get crumbs (alternatively, you can make the dough in a large bowl with your hands or with a pastry blender). Add oil and 3 Tbsp water and mix briefly to form a dough. If the mixture is too dry, you can add 1 more Tbsp water.

Step 3

Put flour, cocoa powder, powdered sugar, baking powder, salt and butter in the bowl of a food processor and mix until you get crumbs (alternatively, you can make the dough in a large bowl with your hands or with a pastry blender). Add oil and 3 Tbsp water and mix briefly to form a dough. If the mixture is too dry, you can add 1 more Tbsp water.

Step 4

Have two large parchment paper pieces ready (about 12×16 inch). Work with half of the dough at a time. Flatten the first half into a disk with your hands, then put the dough between the two pieces of parchment paper and use a rolling pin to roll it to a very thin (1/16 inch) rectangle. Gently remove the top piece of parchment paper.

Step 5

Place the long side of the rectangle close to you. Use an icing spatula to spread half the Nutella or hazelnut or Kinder spread all over the rolled dough. On the long side close to you, place a row of Kinder chocolates one next to the other.

Step 6

Starting from the Kinder side, roll the dough rectangle into a log and transfer to the baking sheet. Repeat with the second half of the dough. Put the baking sheet in the fridge for 1 hour (or up to a day, but be sure to wrap the baking sheet with plastic wrap).

Step 7

Use a knife to mark ½-inch slices on the top of the log.

Step 8

Bake for 20 minutes. Transfer to a cooling rack and let cool completely for a couple of hours before slicing into cookies. Wipe the knife clean between each slice to keep the cookies clean.

Step 9

Dust cookies with powdered sugar.