In a small bowl, combine the water and 1 teaspoon of sugar. Stir in the yeast and let sit for 5 to 10 minutes, until mixture is foamy. (If your mixture doesn’t foam, your yeast may be dead - get new yeast and try again.)

In a medium bowl, stir together 3 ¾ cups of flour, ½ cup sugar, eggs, the ¼ pound melted butter, milk, sour cream, salt, and the yeast mixture, and mix well. Cover and refrigerate 1 hour.

In a medium bowl, use a wooden spoon or sturdy plastic spatula to thoroughly mix 2 sticks (½ pound) very soft butter and remaining ½ cup flour until no dry spots remain. On a generously floured surface, roll out refrigerated dough into a 12 x 18 inch rectangle. Use a spatula to spread butter mixture over refrigerated dough. Roll into a log until you can no longer see the butter, then pat into a flat rectangle about 1 inch thick, wrap with plastic wrap, and refrigerate overnight or at least 8 hours. 

Preheat oven to 375 degrees. Line two baking sheets with parchment paper.

In a medium bowl, mix cinnamon and remaining 1 cup sugar. Transfer dough to a lightly floured surface and divide in two. Keep one half refrigerated while you roll the other half into a circle about 13 inches in diameter and a scant 1/4 -inch thick, Gently spread 2 tablespoons of the remaining very soft butter over the dough, then sprinkle with half of the cinnamon-sugar. Top with half of the walnuts in an even layer, pressing gently so that it all adheres. Using a pizza cutter or a very sharp knife, cut the circle into 12 even triangular slices. Starting at the wide end, tightly roll each slice toward the center of the circle. Place 2 inches apart on prepared baking sheets with the point underneath and curve the ends slightly toward the center to form a crescent. Repeat with the remaining dough and filling. 

Bake for 20 to 25 minutes until firm and golden. Let cool for 10 minutes on baking sheet, then transfer to wire racks to cool completely.