Adapted from theflavorofvanilla.blogspot.com
teaspoons instant dry yeast
cup warm water
cup vegetable oil
Dissolve yeast in the warm water. Combine egg yolks plus three eggs (the remaining egg is for an egg wash) and whisk together lightly. Pour this into the dissolved yeast mixture and add the vegetable oil, sugar, salt, and 3 1/2 cups of flour. Using a stand mixer attached with a paddle attachment, begin kneading the dough on low speed, adding the remaining flour until the dough pulls cleanly away from the edges. Continue kneading for 8 minutes. Oil a large bowl and add the dough - allow to rise for 90 minutes, or until doubled in size. Punch the dough down, and cut into 16 equal pieces. Lightly knead each individual piece to get rid of air pockets (they rise quickly) and roll into an 18-inch long tube shape. Fold one end over the other, and form the knot by tucking one end underneath the formed circle, and the other on top. Place 8 on each of two baking sheets lined with parchment paper. Maximize empty space - they'll double in size during proofing. Allow to proof for 45 minutes, and preheat the oven to 375ºF with a rack placed in the lower third. Whisk the last egg and brush the tops of each knot with the egg wash. Bake for 12 minutes, then place onto cooling rack to cool.