Combine flour, pumpkin, lukewarm milk, egg, 42 g softened butter, sugar, instant yeast, and salt in a large bowl. Mix, then knead about 8–10 minutes by hand or with a dough hook until smooth and elastic, slightly tacky but able to hold a ball. Use a scraper rather than adding large amounts of flour.

Use part of the reserved 4 g butter to grease a bowl. Place dough inside, cover, and let rise in a comfortably warm place about 75 minutes, until visibly expanded and nearly doubled. A cooler room may need longer.

Grease a 9-by-13-inch baking dish with the remaining greasing butter. Gently deflate dough and divide into 12 equal portions, approximately 72 g each before finishing butter. Tuck edges underneath to form smooth balls. Arrange in three rows of four.

Cover and let rise about 45 minutes, until very puffy and nearly touching; allow longer if needed. Near the end, heat oven to 350°F (177°C).

Uncover and bake 25–30 minutes, until golden and a thermometer in a center roll reads at least 190°F (88°C). Cover loosely with foil if tops brown too quickly. Brush with 14 g melted butter. Cool 10 minutes before serving.

Cool leftovers completely, wrap airtight, and keep at room temperature up to 2 days for best quality, or freeze for longer storage. Do not taste raw dough; wash hands and equipment after handling flour and egg.