Butter 20 cups of 2 standard muffin tins; dust with granulated sugar, tapping out excess. In a bowl, combine both sugars, zest, cinnamon, and salt.
Divide chilled dough in half. Roll out one half (keep other half refrigerated) on a lightly floured surface into a 12-by-7-inch rectangle. Spread half of butter over dough, leaving a 1/4-inch border. Sprinkle with half of cinnamon mixture (it will seem like a lot), patting to adhere. Starting on a long side, roll dough into a cylinder. Pinch edges to seal; trim ends. Cut into 10 disks. Place, cut-side down, in prepared tin. Repeat with remaining dough and filling. Drape with buttered plastic wrap; let rise in a warm spot until doubled in bulk, about 2 hours.
Preheat oven to 375 degrees. Bake until golden brown, about 13 minutes. Brush tops with butter; toss rolls in granulated sugar. Let cool slightly on a wire rack before serving.