4 1/2 tsp dry active yeast
1/4 cup warm water
1 1/4 cup buttermilk
1/3 cup sugar
1 stick butter, softened
1.5 tsp salt
1/2 tsp baking soda
4 1/2- 5 1/2 cups flour
1 egg yolk + 1 tbsp warm water for wash
Dissolve the yeast in the water and let sit for five minutes, until foamy. While the yeast is resting, very carefully scald the buttermilk (just heat on medium/low heat until there are bubbles around the sides of the pot) and add the butter, stirring so the butter melts completely. Take off the heat and add the sugar. Let cool for 5-10 minutes.
In a large bowl, mix together the flour, baking soda and salt. "Hide" the salt at the bottom of the flour then pour in the yeast, followed by the semi-cooled buttermilk and the eggs. Knead by hand or with an electric mixer until smooth and elastic, about six minutes. Add more flour if the dough seems really sticky, but keep in mind that this is a sticky and soft dough by nature. I think I added an extra 3/4 cup flour while my mixer was running on low.
Spray another bowl with cooking spray and place the dough ball at the bottom. Cover with a dish cloth and let rise in a warm spot for an hour, or until doubled in size.
Preheat oven to 375.
Punch down dough on a floured surface and divide into 2-oz balls (use a food scale if you have one and if not, just do golf ball sized balls). Make knots out of the dough (see photo above) and place on a lined baking sheet.
Brush each knot with egg yolk and water and bake for 20-25 minutes until golden brown.