In a large bowl, mix the yeast with the warm milk and let it sit for 10 minutes. Add the sugar and flour. Mix until smooth.

Lightly flour the surface, cover, and let rest for 30 minutes in a warm, draft-free place.

In the bowl of a stand mixer fitted with a dough hook, add the lightly beaten eggs. Add the vanilla and Skyr, and mix. Add the yeast and flour mixture. Start kneading and gradually add the remaining flour. Knead for 3 minutes on medium speed, then add the salt and knead for another 3 minutes.

Cover the bowl and let the dough rise for 30 minutes.

Place the dough on a lightly floured work surface and punch it down. Fold in the chocolate chips. Divide the dough into 3 equal pieces. Roll each piece into a rope and braid them together. Place on a baking sheet lined with parchment paper. Let rise again for 20 minutes at room temperature, away from drafts.

Preheat the oven to 350°F (180°C). Brush with the egg yolk and sprinkle with pearl sugar. Bake for 20 to 25 minutes, watching closely.

Let cool and enjoy!