For the Rolls:
4¼ cups all-purpose flour, divided
⅓ cup granulated sugar
2¼ teaspoons active dry yeast
1 teaspoon kosher salt
⅔ cup evaporated milk
⅓ cup water
6 tablespoons unsalted butter, cubed and softened
2 large eggs
Streusel topping (recipe follows)
For the Topping:
1½ cups plus 1 tablespoon (8 grams) all-purpose flour, divided
½ cup granulated sugar
⅛ teaspoon kosher salt
7 tablespoons cold unsalted butter, cubed
1 large egg
1 large egg yolk
2 tablespoons finely grated Mexican chocolate
1 teaspoon unsweetened cocoa powder
1 tablespoon firmly packed dark brown sugar
1 teaspoon ground cinnamon
½ teaspoon Chinese five-spice powder
1. In the bowl of a stand mixer fitted with the paddle attachment, beat 2 cups flour, sugar, yeast, and salt at low speed until combined.
2. In a small saucepan, heat evaporated milk, ⅓ cup water, and butter over medium heat until a candy thermometer registers 120°F to 130°F. With mixer on low speed, add hot milk mixture to flour mixture. Increase mixer speed to medium, and beat for 2 minutes. Add eggs and 1 cup flour; beat at high speed for 2 minutes. Gradually add remaining 1¼ cups flour, beating until a soft dough forms.
3. Switch to the dough hook attachment; beat at medium speed until dough is smooth but still sticky, about 5 minutes. Turn out dough onto a lightly floured surface, and knead until very soft, smooth, and no longer sticky, about 1 minute. If dough seems too sticky, add ¼ cup more flour. (Dough should be on the soft side, so don’t add too much flour, or buns won’t be as soft.)
4. Spray a large bowl with cooking spray. Place dough in bowl, turning to grease top. Cover with plastic wrap, and let rise in a warm, draft-free place (75°) until doubled in size, 1 to 1½ hours.
5. Meanwhile, make the streusel topping: In a medium bowl, stir together 1½ cups flour, granulated sugar, and salt. Using a pastry blender, cut in cold butter until mixture is crumbly. In a small bowl, whisk together egg and egg yolk; stir egg mixture into flour mixture until clumps form.
6. Divide mixture into 3 equal portions of 1 cup each. Using hands, form each portion into a paste, making sure all ingredients are well combined and emulsified with no butter chunks left over. Place one portion in a small bowl, and stir in finely grated chocolate and cocoa until combined. Place second portion in another bowl. Stir in brown sugar, cinnamon, five-spice powder, and remaining 1 tablespoon flour. Leave third portion as is.
7. Beginning with plain streusel mixture, divide and shape each portion into 5 balls. (You will have a total of 15 balls.) On a lightly floured surface, press each ball into a 4-inch patty. Place on a large plate, separating layers with plastic wrap or parchment paper to keep from sticking together. Cover with plastic wrap, and refrigerate until ready to use.
8. Line 3 baking sheets with parchment paper.
9. Punch down dough, and turn out onto a lightly floured surface. Divide dough into 15 equal portions, and shape each portion into a smooth ball. Flatten each ball into a 3-inch round, and place on prepared pans. Top with the streusel rounds. Using a small paring knife, carefully cut a scallop shell or crisscross design into streusel, leaving a ¼-inch border. Let rise in a warm, draft-free place (75°F) until almost doubled in size, 45 minutes to
10. Preheat oven to 375°F. Bake until topping is just beginning to brown, 15 to 20 minutes. Serve warm or at room temperature. Store in an airtight container at room temperature for up to 2 days.