3/4 stick unsalted butter, melted, divided
2 teaspoons active dry yeast (from a 1/4-ounce package)
1/4 cup warm milk (105–115°F)
1 tablespoon mild honey or sugar
2 3/4 cups all-purpose flour plus more for kneading and dusting
1 1/2 teaspoons salt
1/3 cup canned pure pumpkin
2 large eggs, divided, plus 1 yolk
1/2 teaspoon grated orange zest
2 tablespoons fresh orange juice
1 tablespoon water
Butter muffin cups with 1 tablespoon melted butter.
Stir together yeast, warm milk, and honey in a large bowl and let stand until foamy, about 5 minutes. (If mixture doesn’t foam, start over with new yeast.)
Mix flour, salt, pumpkin, 1 whole egg, yolk, orange zest and juice, and remaining 5 tablespoon butter into yeast mixture with a wooden spoon or rubber spatula until a soft dough forms. Turn out dough onto a floured surface and knead, dusting surface and your hands with just enough flour to keep dough from sticking, until dough is elastic and smooth, 6 to 8 minutes. Form dough into a ball.
Put dough in an oiled large bowl and turn to coat. Cover bowl with plastic wrap and a kitchen towel and let dough rise in a draft-free place at warm room temperature until doubled, 1 1/2 to 2 hours.
Punch down dough (do not knead), then halve. Roll half of dough on a lightly floured surface with lightly floured hands into a 12-inch-long log (keep remaining half covered with plastic wrap).
Cut log into 6 equal pieces, then cut each piece into thirds. Roll each piece into a 1-inch ball by cupping your hand and pushing dough against work surface as you roll in a circular motion. Put 3 balls side by side in each of 6 muffin cups.
Make more rolls with remaining dough in same manner. Cover rolls with a kitchen towel (not terry cloth) and let rise in a draft-free place at warm room temperature until dough is about 1 inch above rim of muffin cups, 1 to 1 1/2 hours.
Preheat oven to 375°F with rack in middle.
Whisk together remaining egg and water and brush on tops of rolls. (You will have leftover egg wash.)
Bake until golden brown, about 20 minutes. Transfer rolls to a rack and cool at least 20 minutes.
Rolls are best the day they’re made but can be frozen (cool completely, then wrap well) 1 month. Thaw, then reheat on a baking sheet in a 350°F oven until warmed through, 5 to 10 minutes.