Pan de Muerto

Stir together bread flour, all-purpose flour, granulated sugar, salt, and yeast in a stand mixer fitted with the dough hook attachment. Add milk, orange blossom water, orange zest and juice, and 3 eggs; beat on medium-low speed until flour is mostly incorporated, about 1 minute, stopping to scrape down sides as needed. Reduce mixer speed to low; add butter, about 3 tablespoons at a time, beating until fully incorporated after each addition and scraping sides as needed, 1 to 2 minutes. Increase mixer speed to medium, and beat until dough is soft, slightly sticky, and elastic (dough should start to pull away from sides of bowl but may still stick to bottom and sides), about 8 to 12 minutes.

Transfer dough to a large bowl greased with butter. Loosely cover bowl with plastic wrap; let stand in a warm, draft-free place until dough is puffed, about 45 minutes. Chill in refrigerator for at least 8 hours or up to 12 hours.

Remove dough from refrigerator; measure out 24 (5/8-ounce) portions, and shape each portion into a ball (for the bones); cover with plastic wrap or a kitchen towel, and set aside. Measure out 12 (1/4-ounce) portions; shape each portion into a ball (for the tops). Place on a baking sheet; cover with plastic wrap, and transfer to refrigerator until ready to use.

Evenly divide remaining dough into 12 (about 3-ounce) portions, and shape each portion into a ball (for the base). (Keep dough covered while working, and lightly dust hands and surface with flour as needed.) Place 6 (3-ounce) balls on each of 2 parchment paper–lined baking sheets, spacing dough balls at least 2 to 3 inches apart. Loosely cover with plastic wrap, and let stand in a warm, draft-free place until dough doubles in size, 30 to 45 minutes. Preheat oven to 400°F with rack positioned on the top third shelf.

Meanwhile, roll 1 (5/8-ounce) ball into a 4 1/2-inch-long rope, working on a very lightly floured surface and lightly flouring hands as needed. Spread 3 fingers of one hand about 1/2 inch apart, positioning the middle finger in the center of the rope, and press 3 deep indentations into dough. Use your index finger to make impressions deeper if needed until dough resembles a bone. Repeat rolling and shaping process with remaining 23 (5/8-ounce) balls. Transfer dough bones to baking sheet with the 12 (1/4-ounce) balls; cover and return to refrigerator until ready to use.

Using your hand, lightly flatten 6 of the proofed 3-ounce dough balls on 1 baking sheet to about 1-inch thickness. Whisk remaining 1 egg in a small bowl, and lightly brush over flattened dough balls. Remove 12 dough bones and 6 (1/4-ounce) dough balls from refrigerator; arrange 2 bones in an X-shape over the top of each flattened ball, pressing or tucking ends beneath the flattened bases as needed. Place 1 (1/4-ounce) ball in center of each X-shape to create the top; firmly press down to adhere to X-shaped bones.

Place baking sheet in preheated oven, and reduce temperature to 350°F. Bake at 350°F until lightly golden brown and an instant-read thermometer inserted into center of dough registers 190°F, 18 to 20 minutes. Let cool slightly on baking sheet on a wire rack, about 15 minutes. Increase oven temperature to 400°F. Repeat shaping and baking process with remaining 6 (3-ounce) dough balls, remaining 12 dough bones, and remaining 6 (1/4-ounce) dough balls.

Bring piloncillo and 1/4 cup water to a boil in a small saucepan over medium-high, stirring occasionally. Reduce heat to medium; simmer, stirring occasionally, until piloncillo is dissolved, 2 to 3 minutes. Remove from heat. Brush breads evenly with piloncillo syrup. Sprinkle and press granulated sugar or sanding sugar onto bread. Serve.