They look cute, they're easy to make, and they taste great! - agreatdayforcake.tumblr.com
In the bowl of a standing mixer cream the butter and sugar (about two minutes).
Add the egg yolks and vanilla and mix until combined.
With the mixer on low, add the flour and salt. Mix until it forms a soft dough. Transfer the dough on to a lightly floured surface. Shape it into a square and divide it in half.
Transfer each half to a sheet of plastic wrap. Wrap tightly and refrigerate for at least 30 minutes. Unwrap one half of the dough and place on a piece of lightly floured parchment paper.
Roll the dough to 1/4-inch thickness, about 10x8 rectangle. Using a spatula, spread 1/4 cup of Nutella on the dough leaving 1/4-inch edge all around.
Using the parchment as a guide, roll the dough starting from the longest side into a tight log. Wrap the parchment paper around the log and refrigerate for at least 30 minutes or freeze for 15.
Repeat previous step with the remaining half. Preheat oven to 350 degrees F. Line a baking sheet with parchment paper. Unwrap the log and slice into approximately 1/3-inch slices.
Place the slices on the prepared baking sheet 1-2" apart. Bake for 12-15 minutes or until just golden around the edges.
Remove from the oven and let cool. Enjoy!