Add 1 cup water, sugar, salt and yeast in a mixing bowl or mixer. Mix until combined. Slowly add in bread flour. Knead for 5 minutes. Place dough in a greased bowl and spray lightly non-stick spray. Cover and let rise in a warm place for about 30 minutes, or until doubled in bulk. Dough is ready if indentation remains when touched. Punch down dough. On a lightly floured surface, roll into a 16x12 inch rectangle. Cut dough in half, creating two 8x12 inch rectangles. Roll up each half of dough tightly, beginning at 12 inch side, working out any air bubbles as you go. Place 3 inches apart on a greased cookie sheet. Make deep diagonal slashes across loaves every 2 inches. Cover and let rise in a warm place for 30-40 minutes or until about doubled in bulk. Preheat oven to 375 degrees. Whisk together egg yolk and water. Brush over tops of loaves. Bake for 20-25 minutes in a preheated oven, or until golden brown. *Notes from Christina: I just add everything except the flour in a mixer and let it sit for 5 min. Then start adding the flour and mix for several minutes. Form your baguettes and let rise while your oven heats up.