Activate Yeast Mixture:

Mix 2 tbsp yeast, 1 cup warm milk, and 2 tbsp granulated sugar in a small bowl. Let sit until frothy, a few minutes.

Combine Dry Ingredients:

In a large bowl, combine 4 cups flour (560g), yogurt, egg, salt, and 2 tsp vanilla sugar. Begin mixing with the dough hook.

Add Yeast Mixture:

Add 3 tbsp flour (from the extra 5 tbsp) and the yeast mixture. Mix until incorporated.

Incorporate Warm Milk:

Heat the remaining 1 cup milk, then slowly add it to the dough while mixing. Continue for 6-7 minutes until smooth.

Let Dough Rise:

Leave the dough in the bowl; sprinkle with the remaining 2 tbsp flour. Set the bowl in a large pot or sink half-filled with warm water. Cover with a clean cloth or paper towel and let rise 30-40 minutes.

Knead Dough:

Turn the dough out onto a floured surface and knead by hand for 2 minutes.

Shape Donuts:

Roll the dough to ½ inch (1.3 cm) thickness. Cut into rectangles roughly 2 inches by 4 inches (5x10 cm). Slit each rectangle lengthwise, leaving the top intact. Twist and set aside.

Heat Frying Oil:

Fill a large pot with canola oil to about 2 inches deep. Heat over medium-high to 350°F (175°C).

Fry Donuts:

Gently place a few donuts into the hot oil. Fry for 4 minutes, flipping once with a fork, until golden on both sides.

Coat with Sugar:

Remove and drain on paper towels. Toss with a mixture of ½ cup granulated sugar (100g) and 1 tsp vanilla sugar.