In the bowl of a stand mixer fitted with a dough hook, combine the all-purpose flour, potato flour, milk powder, sugar, yeast, and salt. Knead on low to combine, about 30 seconds. Make a well in the center of the dry ingredients.

Pour the water into the well and mix with a rubber spatula until shaggy, 1 minute. Pour in the butter and knead on medium-low for 10 minutes, or until sticky and elastic, using a rubber spatula to scrape down the bottom and sides of the bowl as necessary.

Tip the dough out onto a lightly floured counter. Dust your hands with flour and knead the dough once or twice into a rough ball. Scrape down the bottom and sides of the bowl to remove any excess dough. Spray the bowl with cooking spray and place the dough back in the bowl. Cover with plastic wrap. Refrigerate overnight.

Uncover the dough and discard the plastic wrap. Tip it onto a lightly floured counter. Use a bench scraper to divide the dough into four equal pieces, roughly 5.45 ounces each.

Dust your counter with flour and use a rolling pin to roll one of the dough balls into a thin, 10-inch circle. Place the dough circle on a parchment-lined sheet pan. Use an offset spatula to spread around 3 tablespoons of Nutella across the dough, leaving a ¼-inch border of bare dough around the perimeter.

Roll out a second dough ball into a circle approximately the same size as the first, and place it on top of the Nutella-covered circle like you would if you were making a quesadilla. Spread the top of this dough circle with another 3 tablespoons of Nutella like you did with the first dough circle. Repeat this layering process with Nutella for the third dough ball, but leave the final dough circle bare.

Place a 3-inch round cutter in the center of the bare dough circle to use as a guide. Use a bench scraper or a sharp knife to cut the circle into 16 equal strips (see baker’s notes), making sure to cut through all layers.

Use two hands to pick up two adjacent strips and twist them away from each other 2 times. Repeat with the remaining strips of dough; you’ll end up with eight pairs of strips. Pinch the ends of the adjacent strips to create “points”. You’ll end up with a star shape with eight points. Remove the cutter.

Cover the star loosely with plastic wrap and let rise for 45 minutes, or until doubled in size.

About 30 minutes into the second rise, position a rack in the center of the oven and preheat the oven to 400°F.

Bake the star bread for 18 to 20 minutes, or until golden brown. An instant read thermometer inserted into the center of the bread should register 200°F. Cool on a wire rack while you make the simple syrup.

In a small sauce pot over medium heat, whisk the sugar and water until the sugar is completely dissolved. Bring to a boil. Remove from heat and immediately use a pastry brush to brush the syrup over the still-warm star bread. Serve warm or at room temperature. The star bread can be stored at room temperature in an airtight container for up to 1 day. After that, refrigerate for up to 2 days more.