Dissolve yeast in milk in a large bowl; let stand 5 minutes.
Add sweet potatoes, 1 tablespoon butter, salt, and egg yolks, stirring mixture with a whisk.
Lightly spoon flour into dry measuring cups; level with a knife. Add 4 1/2 cups flour; stir until a soft dough forms.
Turn dough out onto a floured surface. Knead until smooth and elastic (about 8 minutes); add enough of remaining flour, 1 tablespoon at a time, to prevent dough from sticking to hands (dough will feel very soft and tacky).
Place dough in a large bowl coated with cooking spray, turning to coat top. Cover and let rise in a warm place (85°), free from drafts, 45 minutes or until doubled in size. (Gently press 2 fingers into dough. If indentation remains, dough has risen enough.) Punch dough down. Cover and let rest 5 minutes.
Line 2 baking sheets with parchment paper. Divide dough into 24 equal portions. Working with 1 portion at a time (cover remaining dough to prevent drying), shape each portion into a 9-inch rope. Carefully shape rope into a knot; tuck top end of knot under roll. Place roll on a prepared pan.
Repeat procedure with remaining dough, placing 12 rolls on each pan. Lightly coat rolls with cooking spray; cover and let rise 30 minutes or until doubled in size.
Preheat oven to 400°.
Uncover rolls. Bake at 400° for 8 minutes with 1 pan on bottom rack and 1 pan on second rack from top. Rotate pans; bake an additional 7 minutes or until rolls are golden brown on top and sound hollow when tapped.
Remove rolls from pans; place on wire racks. Brush rolls with 2 tablespoons butter. Serve warm or at room temperature.
Tasty, nice texture, and very, very pretty. Family loved these but I was less excited due to low sugar content. I did add 1 T. Sugar to the liquid ingredients but still felt they were not sweet enough. Also used fresh mashed sweet potato rather than canned. Added full 4.5 c. Of flour an that was too much -- had to add milk until the dough would come together. So I agree with previous reviewer that full amount is too much. Baked for 14 min and agree closer to 10 or 12 might be better.
Fantastic, easy to make rolls. I also made 2 other types of bread for this Thanksgiving meal - all others went untouched by the family, while the rolls were gone! They were a huge hit with kids and adults alike. Definitely a great recipe for quick and very pretty rolls. Plan to try substitution with freshly ground whole wheat four.
Everyone always loves these. Made them for Thanksgiving and Christmas both last year and this year. Fairly easy. I never need as much flour as the recipe calls for, and I usually keep the bowl on my stove (which is usually on for the turkey or ham) to assist the rising. I knot and cover them, and then leave them until the meat is out of the oven; slip them in the oven while the meat is resting (I cook for no more than 10 minutes), butter, and serve! Last year I even froze some of the little dough balls after the first rising to make at a later date -- still came out great!
These are fantastic! They're fun to make and they look great. I actually left them in the refrigerator overnight on a baking sheet after shaping them and allowing for rising and popped them in the oven right before dinner. The color adds a lot to the table, and they were great for little leftover turkey sandwiches. I will be making these every year from now on.