Heat the water and milk just until warm (105°F). Pour into a large bowl and stir in the yeast and a tablespoon of sugar. Allow to sit for 5 minutes until the yeast begins to bubble.

Stir the remaining sugar and the 1/2 cup melted butter into the yeast. Add the egg yolks and vanilla and mix well.

Stir in 3 ½ cups of flour and salt until well combined. If the dough is too sticky, add a little more flour until a soft dough forms.

Cover the dough with a towel and place in a warm place. Allow to rise until doubled, about 1 hour.

Dust a large surface with flour and roll the dough out into a 14x18 inch rectangle.

Melt the remaining 2 tablespoons of butter and brush over the bread. Use a sharp knife or a pizza cutter and cut 1 inch wide strips down the length of the dough.  

Line a large cookie sheet with parchment paper or a silicone baking mat. Roll each strip up and into a roll and place on the cookie sheet. Leaving about 3 inches between each roll for spreading.

Brush the tops with any leftover melted butter and cover lightly with a tea towel. Allow bread to rise in a warm place until nearly doubled, about another 45 minutes to an hour.

Heat the oven to 350°F and place the rolls in the pre-heated oven.  Bake until lightly browned, between 12 and 18 minutes.

Remove and dust with powdered sugar. Serve warm or let cool completely before storing.