In the bowl of a stand mixer, combine the warm water, honey and yeast. Let stand for 5 minutes while the yeast creates a foam on top of the water. Add the egg yolks and vanilla and mix together with the paddle attachment.
Separately, whisk together the flour, salt and cinnamon then slowly add the dry mixture to the mixer and beat on low until everything is combined.
Change to the dough hook and knead on medium speed for 5 minutes, until the dough is smooth and a bit sticky. Place the dough in a greased bowl, cover with plastic wrap or a clean towel and allow to rise for 1 hour in a warm spot.
When the dough has doubled in size, transfer to a clean surface lightly dusted with more spelt flour. Roll the dough out to 1/4 inch thick and cut circles with a doughnut or cookie cutter, or you can use the top of a glass drinking cup. You can re-roll any scraps and cut more circles one more time before the dough gets too tough so try to cut as many doughnuts out of the first batch. Place the cut out doughnuts (and holes) on a parchment lined baking sheet and allow to rise 30 more minutes before frying.
To fry, heat the oil (canola and vegetable are fine) in a heavy bottom pot with a thermometer attached to keep track of the temperature. You want the oil to be between 370 and 375 degrees F. Have a wire cooling rack lined with paper towels and a slotted spoon ready next to the pot.
Start by frying one doughnut for around 1 minute on each side to make sure the oil is at the right temperature and then continue to fry 3-4 doughnuts at a time, based on the size of the pot. You don’t want to overcrowd the pot or the oil temperature will drop and you will end up with oily doughnuts. Remove all doughnuts with the slotted spoon and place on the paper towels to drain.
While the doughnuts are cooling, combine the honey and water in a small saucepan and bring to a simmer, whisking occasionally. Simmer the honey simple syrup for 10 minutes, until it has thickened into a syrup. Allow to cool slightly before dipping the doughnuts on both sides and placing them on a wire rack to set.
Leftover doughnuts (if there are any) can be stored for one day in a plastic storage bag but will definitely not taste as good the next day. Doughnuts are always best fresh!