1. To make the starter: Combine the starter ingredients in a medium-large mixing bowl, cover the bowl, and let the starter rest for 1 hour, until it's bubbly.

  2. To make the dough: Add the dough ingredients to the starter, and mix and knead to form a sticky, elastic dough. Resist the urge to add more flour. Yes, this dough is sticky! It won't clean the sides of the bowl as dough for a traditional sandwich bread (or even brioche dough) will.

  3. Let the dough rise, covered, in the mixing bowl (or in another bowl, if desired) for 60 to 90 minutes, or until it's doubled in size; it may be a bit slow, so allow it plenty of time.

  4. To make the topping: Mix together the sugar, salt, cinnamon, and softened butter until smooth. Stir in the flour in two additions, mixing to make a thick paste. Note: You'll use the egg white later. Cover the bowl and set the topping aside.

  5. Transfer the dough to a greased or floured work surface, and divide it into 10 pieces. Roll each into a ball.

  6. Place the balls of dough onto a greased or parchment-lined baking sheet, leaving some space between them.

  7. To finish the rolls: Divide the topping into 10 portions. Flatten each portion into a 3" to 4" disk by placing portions between two pieces of parchment or wax paper, and rolling with a rolling pin or flattening with your fingers.

  8. Lightly beat the egg white. Brush the top of each shaped roll with some of the beaten white, then add one of the disks of topping. Flatten the rolls slightly. 

  9. Let the rolls rise for 30 to 45 minutes, covered, until they're noticeably puffy.  

  10. While the rolls are rising, preheat your oven to 350°F with a rack in the center.

  11. Just before baking, use a sharp knife or lame to cut designs into the topping; don't cut into the dough below. 

  12. If you have a second sheet pan of the same size, nest the pan of rolls into it; this will help prevent their bottoms from over-browning as they bake.

  13. Bake the rolls for 18 to 24 minutes, until they're golden brown. Remove them from the oven, and let them rest on the pan until they're cool enough to handle.  

  14. Enjoy rolls warm, with jam. Store any leftovers, well wrapped, for three days at room temperature; freeze for up to a month.