Step 1In the large bowl of a mixer with a dough hook (you can also do this by hand), stir together the flour, salt, sugar and yeast, then gradually beat in one-half cup plus 2 tablespoons water and the eggs. Beat the dough for about 5 minutes, until it forms a loose, elastic mass around the dough hook.
Step 2Turn the dough out onto a floured board and form a ball. Place the dough in a buttered bowl and loosely cover with plastic wrap. Set aside in a warm place until the dough doubles, about 2 hours.
Step 1Put the starter, 1 cup of sugar and the three-fourths cup plus 2 tablespoons softened butter into a large mixing bowl and mix, by hand or with a stand mixer, until well-incorporated. Gradually beat in the flour and the egg yolks with water, alternating a little of each until the flour and yolks are completely incorporated. Beat in one-quarter cup water, the orange flower water and zest until combined. Mix the dough for a few minutes until it is a shiny and sticky mass that just holds its shape. Turn out the dough onto a lightly floured surface and form into a round.
Step 2Wash, butter and flour the bowl, and return the dough to it. Cover with plastic wrap and set aside in a warm place for about 1 1/2 hours, until doubled.
Step 3Butter 4 baking sheets. Turn the dough out onto a floured board and divide it into two equal portions. Set aside one portion, loosely covered with plastic wrap so it does not form a skin.
Step 4Remove one-fourth from the remaining portion of dough and set it aside. Roll the larger portion into a smooth ball, then press it into a circle about 8 inches in diameter and 1 inch thick. Gently flatten the outside edge of the circle to form a narrow rim about one-fourth-inch thick, then transfer the round to one of the greased baking sheets.
Step 5Divide the smaller portion into 4 equal parts. Roll one into a ball and place on another greased baking sheet. Roll the three remaining pieces into strips about 8 inches long, each with a few crimps to form "bones." Add these to the smaller ball on the baking sheet.
Step 6Repeat with the remaining portion of dough, forming a larger, rimmed round and dividing the smaller portion into one ball and three "bones." Loosely cover each baking sheet with plastic wrap and place in a warm place for one hour to rise.
Step 7Heat the oven to 375 degrees. Unwrap the first portion of dough (large and small round and three bones) and arrange the "bones" in a spoke-like pattern over the large round. Place the smaller round -- the "skull" -- in the center of the spokes and poke two holes in the center for "eyes." Repeat with the remaining portion of dough to form a second decorated round. Brush the decorated rounds with the beaten eggs.
Step 8Bake the rounds until the loaves are well-browned and springy, about 25 to 30 minutes. Turn off the oven, open the door and allow the bread to sit for 5 minutes. Remove from the oven, brush with the melted butter and sprinkle generously with the remaining sugar. Cool completely, then serve.