In a small bowl, mix together the yeast and the sugar. Pour in the milk, egg yolk, and butter then mix gently to combine. Allow the mixture to sit for about 10 minutes. You should see a nice layer of foam after this point. (If you do not, you may need new yeast)

In your mixer, whisk together the flour and salt. Pour in the milk mixture and mix with a paddle attachment to combine until the dough pulls away from the bowl. Use a dough hook to knead for about 10 minutes. If you do not have a stand mixer, you can knead by hand for about 15 minutes. The dough should be smooth, soft, and only slightly sticky.

Lightly grease a bowl with oil and place the dough inside. Cover with plastic wrap. Leave in the refrigerator overnight (or in a warm, dry area for one hour).

Lightly grease a cast iron skillet. Preheat the oven to 375 degrees F. Allow the dough to warm for a few minutes before deflating the dough and rolling out to about 18” by 12” on a lightly floured surface.

Spread the Nutella over the dough, leaving a one inch border all around. Evenly place the raspberries over the Nutella, the very gently press down to ensure they stick. Tightly roll the dough lengthwise so you have an 18 inch long log. Cut the log in half, leaving about an inch at one of the ends keeping the two separate pieces attached. Twist the pieces slightly so that the cut sides are facing up. Place one of the halves over the other, ensuring the cut sides remain facing up. Continue twisting the pieces in this manner until you can no longer twist. Bring the end pieces up to the other uncut end to that the bread forms a circle. Transfer the bread to the cast iron skillet and allow to rise for another 30 minutes.

Brush with the egg wash, then sprinkle with the turbinado sugar. Bake for about 25 – 35 minutes, or until a golden brown. Remove and allow to cool completely before adding the powdered sugar.