Combine 5 cups flour, 1 cup warm milk, 1 cup sugar, 4 eggs, 2 1/4 teaspoons yeast, 1 1/4 teaspoons salt, and 2 tablespoons orange flower water in the bowl of a stand mixer fitted with the bread hook attachment. Start on low and mix until the dough comes together. Increase the speed to medium and knead for 1 minute. Stop the mixer. If the dough seems too sticky, is like really thick cake batter, and not pulling away from the sides of the bowl at all, add more flour, 1/2 cup at a time until the dough is soft and a little sticky but firm enough that it is starting to pull away from the sides of the bowl, but not clean the sides or pull away from the bottom of the bowl.
Return the mixer to medium and start adding the 1 stick of butter, 1 small piece at a time, letting the first one blend in before adding the next. Once all the butter is added, continue kneading for about 5 more minutes on medium speed.
First rise: Grease a large bowl and transfer the dough to the bowl. Cover with plastice wrap and leave it in the warmest area of they kitchen until it doubles in size, about 1-3 hours.
Second rise: Place dough on a clean counter and flatten into a rectangle. Sprinkle the chopped tropical fruit on top and fold the dough over the fruit. Knead the dough on the counter until the fruit is evenly distributed. Return to the greased bowl (add a bit more oil if the bowl is dry), cover with plastic wrap, and let it rise again for another 1-2 hours. (At this point you can also cover the dough with plastic wrap and let it rise overnight in the refrigerator. Just let it come to room temperature before proceeding.)
Shaping: Flip the dough out on to a counter. Cut the dough into one 12-ounce piece (this will be for the decorations) and twelve (4-5 ounce) pieces (these will be for the loaves). Shape these twelve pieces into balls and place on 2 large baking sheets lined with parchment paper. Press down on the balls to flatten into discs.
Sprinkle 2 tablespoons of flour over the remaining piece of dough and knead it in with your hands on the counter. This piece will be used for the decorations and needs to be stiffer. Divide this piece of dough into 36 equal pieces. Roll twelve of them into balls for the skulls. Shape the remaining pieces into snakes then create three indentations in each by rolling it back and forth with your fingers to create a bone shape.
Brush the top of each loaf with water in a line across the loaf. Attach one bone using the water to adhere. Brush another line of water across the loaf criss-crossing where you placed the first bone and adhere the second bone to the top of each loaf. Brush the spot on top of each loaf where they meet with water and adhere the skull to each loaf. Cover the bread with a clean kitchen cloth and let rise again, another 1-2 hours.
Bake: Heat the oven to 350°F. Once oven is hot, bake the pan de muertos for about 30-35 minutes or until bread is firm, golden brown and sounds hollow when you tap on the bottom of the loaf. and baked through. For a more accurate test, the bread is done when an instant-read thermometer reads the center of the loaf as 195–200°F (90–93°C).
Cool: Transfer loaves to a wire rack and let cool.
Decorate: Brush the top of the loaves with melted butter and while holding each loaf over a bowl to catch any sugar, sprinkle the loaves generously with more sugar or sesame seeds.
Cover leftover bread tightly and store at room temperature for 6 days or in the refrigerator for up to 10 days.