Step 1

In a small bowl add the water and ½ teaspoon of sugar, sprinkle the yeast on top. Let sit for 10 minutes then stir to combine.

Step 2

In the stand mixer bowl whisk together the flours, zest and the remaining sugar, add the vanilla, egg yolk and milk, start to knead add the yeast mixture and knead two minutes on speed #2 add the softened butter and the salt, continue to knead for 8 minutes to form a compact dough.

Step 3

Move the dough to a lightly butter bowl, cover and let rise in a warm draft free area until tripled for approximately 2-3 hours.

Step 4

Transfer the dough to a lightly floured flat surface and roll to ½ inch / 1¼ cm thickness, using a donut cutter or a round cookie cutter (3½ inches / 9 cm) and a round piping tip (1 inch / 3 cm) cut out the donut shapes.

Step 5

Place the donuts on a parchment paper lined baking sheet 3 inches / 7½ cm apart. Cover and let rise for 1 hour or until doubled.

Step 6

Pre-heat oven to 350F / 180C.

Step 7

Bake the donuts for 12-15 minutes or until golden brown. Move immediately to a wire rack to cool. Dust with powdered sugar before serving. Enjoy!