Warm 1/4 cup of the apple cider to about 100-110 degrees and place in the bowl of a stand mixer.

Sprinkle the yeast over the apple cider and let stand for about 5 minutes.

Add all-purpose flour, additional 1/4 cup apple cider, milk, butter, egg yolks, sugar and salt and mix on low until a dough forms or comes together like a ball.

Place the dough in a greased bowl and cover with a tea towel or plastic wrap.

Sit dough aside in a warm place to rise for 1 1/2 hours.

Once dough has doubled in bulk, place on a floured surface.

Roll dough out to about 1/2" thickness.

Using a donut cutter or roung cookie cutter, cut out as many doughnuts as possible. Do not re-roll dough.

Place cut doughnuts on a cookie sheet lined with parchment paper.

Cover doughnuts with a tea towel and sit them in a warm place to rise 20-30 minutes or until they look puffy.

When ready to fry, heat oil in a large dutch oven or pot until it reaches 350 degrees.

While waiting for oil to heat, mix together sugar and cinnamon and place in a shallow dish.

Fry the doughnuts, about 1-2 minutes on each side.

Drain the doughnuts on a paper towel-lined plate to let cool for a few seconds.

Toss the doughnut in the cinnamon sugar mixture, being sure to coat the whole thing.