Place the butternut squash in a medium microwave safe bowl and microwave on high for 2 minutes. Stir and microwave for another 3 minutes or until very soft and easy to mash. Mash with a fork until well mashed.
Combine 3/4 cup flour, sugar, dry yeast and salt in a large mixer bowl and stir until blended.
Combine milk, water and butter in a small microwave-safe bowl. Microwave on HIGH in 15 second increments until very warm but not hot to the touch (120° to 130°F. Butter won’t melt completely).
Add the milk mixture to the flour mixture along with the butternut squash mash and the sage.
Beat 2 minutes at medium speed of electric mixer, scraping bowl occasionally. Add 1/4 cup flour; beat 2 minutes at high speed. Stir in just enough of the remaining flour (1 to 1-1/4 cups) so that the dough will form into a ball.
Knead on lightly floured surface until smooth and elastic and springs back when lightly pressed with 2 fingers, about 6 to 8 minutes. Cover with a towel; let rest for 10 minutes.
Cut dough into 12 equal pieces; shape into balls using your hands. Place in greased 8-inch round or square pan. Cover with towel; let rise in warm place until doubled in size, about 10 minutes.
Bake in preheated 375ºF oven for 20 minutes or until golden brown. Remove from pan by running a knife around the edges and invert onto wire rack; brush with additional melted butter, if desired. Serve warm.
Recipe Notes: The milk mixture took us 4, 15-second increments in the microwave until it was warm enough.
It took us 1 cup of flour to make the dough form into a ball.