Preparation Combine milk, 3 tablespoons butter and sugar in heavy medium saucepan. Stir over low heat until butter melts and mixture is heated through. Whisk in squash. Remove from heat and cool until thermometer inserted into mixture registers 125°F to 130°F, about 5 minutes. Mix flour, yeast and salt in food processor. With machine running, add squash mixture through feed tube; process until ball forms. Continue to process 45 seconds longer to knead dough. Butter large bowl. Add dough to bowl and turn to coat. Cover bowl with towel. Let dough rise in warm draft-free area until doubled, about 50 minutes. Preheat oven to 375°F. Butter two 9-inch-diameter cake pans. Punch down dough. Turn dough out onto lightly floured work surface. Divide dough into 24 equal pieces. Form each piece into ball. Arrange 12 balls in each prepared cake pan, spacing apart. Melt remaining 2 tablespoons butter in small saucepan over low heat. Brush rolls with 1/3 of melted butter. Cover pans loosely with foil. Let rolls rise in warm draft-free area until doubled, about 20 minutes. Brush rolls again with 1/3 of melted butter. Bake rolls uncovered until golden brown, about 25 minutes. Transfer pans to rack. Brush rolls with remaining melted butter. (Can be prepared 2 weeks ahead. Cool rolls completely in pans. Cover pans with foil and freeze. Thaw rolls; then reheat rolls, covered in pans, in 350°F oven about 10 minutes.) Serve rolls warm.
Preparation Combine milk, 3 tablespoons butter and sugar in heavy medium saucepan. Stir over low heat until butter melts and mixture is heated through. Whisk in squash. Remove from heat and cool until thermometer inserted into mixture registers 125°F to 130°F, about 5 minutes. Mix flour, yeast and salt in food processor. With machine running, add squash mixture through feed tube; process until ball forms. Continue to process 45 seconds longer to knead dough. Butter large bowl. Add dough to bowl and turn to coat. Cover bowl with towel. Let dough rise in warm draft-free area until doubled, about 50 minutes. Preheat oven to 375°F. Butter two 9-inch-diameter cake pans. Punch down dough. Turn dough out onto lightly floured work surface. Divide dough into 24 equal pieces. Form each piece into ball. Arrange 12 balls in each prepared cake pan, spacing apart. Melt remaining 2 tablespoons butter in small saucepan over low heat. Brush rolls with 1/3 of melted butter. Cover pans loosely with foil. Let rolls rise in warm draft-free area until doubled, about 20 minutes. Brush rolls again with 1/3 of melted butter. Bake rolls uncovered until golden brown, about 25 minutes. Transfer pans to rack. Brush rolls with remaining melted butter. (Can be prepared 2 weeks ahead. Cool rolls completely in pans. Cover pans with foil and freeze. Thaw rolls; then reheat rolls, covered in pans, in 350°F oven about 10 minutes.) Serve rolls warm.