Measure milk into a liquid measuring cup and add butter. Microwave for 1 minute and mix until butter melts completely and is 110-120 degrees F.
In the bowl of a stand mixer fitted with the paddle attachment, combine the milk mixture, yeast, and about 1 tablespoon of the sugar. Cover with a towel and let the yeast activate for 5 minutes.
Mix in the egg yolks, remaining sugar, and salt. Add 2 1/2 cups flour and mix until combined. Switch to a dough hook, add the remaining 1/2 cup flour and knead for 5 minutes on medium until a soft smooth dough forms.
Grease a mixing bowl with cooking spray and place the dough inside. Flip it over so that the top of the dough is greased. Cover bowl with a clean towel and let it rise until about double in bulk (50-60 minutes).
Preheat oven to 375 degrees F and grease a muffin tin.
Divide dough in two. Roll one half out into a 14x10 inch rectangle. Heat Nutella up in the microwave for about 20 seconds so it's a little thinner and then spread it over the dough within 1/4 inch of the sides. Sprinkle on the hazelnuts.
Roll out the remaining dough into another 14x10 inch rectangle and place on top of the filling. Press the edges together to seal and then cut into 12 (14-inch) strips. This works best using a pizza cutter and cutting the dough into 4 long strips and then cutting each of those into 3 strips.
Take each strip and twist it into a coil (about 7 twists). Spiral each twist down into the muffin cup and tuck the end down into the middle.
Mix the egg white with 1 tablespoon water and then brush over the tops of the twists. Bake for 14-16 minutes until golden brown. Immediately remove from muffin cups and place on cooling rack. Cool for 5 minutes, dust with powdered sugar, and serve warm.
Yeast hydration temperatures above 130 degrees Fahrenheit destroy active cultures instantly, rendering fermentation impossible before mixing even begins. Monitoring the liquid temperature with an instant-read thermometer ensures the yeast remains viable when combined with dairy and sugar. Bakers frequently sabotage laminated or enriched doughs by ignoring liquid thermal thresholds, which halts carbon dioxide production entirely and yields dense, heavy pastries instead of light, airy layers. Furthermore, rolling the dough into precise fourteen-by-ten-inch rectangles guarantees uniform thickness across all twelve portions, preventing uneven baking rates in the oven.
Managing Nutella and Fillings
Spreading cold chocolate spread tears delicate yeast doughs immediately upon contact. Warming the hazelnut spread briefly in a microwave for twenty seconds alters its viscosity enough to allow smooth application without puncturing the underlying gluten network. Leaving a quarter-inch bare border along the edges of the rectangle prevents the filling from escaping during the subsequent twisting and baking phases. Although many cooks attempt to assemble these pastries without chilling the filling layer, working quickly while the dough remains cool keeps the butter from melting out prematurely.
Baking and Structural Integrity
Coiling each cut strip precisely seven times distributes the interior layers evenly throughout the cavity of a standard greased muffin tin. Brushing the shaped dough with an egg white wash diluted with one tablespoon of water creates a glossy exterior finish while promoting a deep golden-brown crust during the sixteen-minute bake. Removing the pastries immediately from the hot metal cups prevents the bottom crusts from steaming and turning soggy against the residual heat of the pan.