Mix Dry Ingredients:

In a stand mixer bowl, whisk together flour, 1/2 cup sugar, and rapid-rise yeast. Dot the surface with softened butter cubes.

Combine Wet Ingredients:

In a separate bowl, whisk milk, eggs, egg yolk, almond extract, orange zest, and salt until combined.

Knead Dough:

Pour the wet mixture into the dry ingredients. Using the dough hook, mix on low for 10 minutes until a dough forms. Lightly oil your hands and knead the dough into a ball for about 2 minutes.

First Rise:

Transfer the dough to a greased bowl, cover with plastic wrap and a towel, and let it rise in a warm spot for roughly 2 hours until doubled.

Shape and Second Rise:

Deflate the dough. On a clean surface, knead briefly into a ball, then roll out to a rectangle. Use a 3-inch (7.6 cm) cutter to stamp out rounds. Place each on a parchment square on a baking sheet, cover, and let rise another 45 minutes.

Fry Bomboloni:

Meanwhile, pour 8 cups vegetable oil into a large pot and heat to 345°F (175°C). Fry the bomboloni for about 2 minutes per side. Remove with tongs and transfer to a paper towel-lined rack.

Fill with Nutella:

While still warm, roll the bomboloni in the remaining sugar. Fit a piping bag with a round tip and fill it with Nutella®. Pierce a small hole in the side of each bomboloni and pipe in the filling. Serve warm for best results.