Combine 3 cups flour, sugar, salt and undissolved yeast in a large mixer bowl. Heat milk, water and butter until very warm (120° to 130°F). Butter does not need to melt completely. Add to flour mixture with eggs. Beat for 2 minutes. Gradually add remaining flour until a soft dough forms.
Knead on lightly floured surface until dough is smooth and elastic, about 6 to 8 minutes. Cover and let dough rest 10 minutes.
For the Filling, mix sugar and cinnamon in a small bowl. Set aside.
Grease two 13 x 9-inch pans (or four 8 x 8-inch pans). For gift giving, disposable baking pans will work great!
Divide dough in half. Roll each half into 15 x 10-inch rectangle on lightly floured surface. Spread with half the butter and top with half the cinnamon-sugar filling, pressing gently into dough. Roll up tightly, sealing edges. Cut into 12 equal slices and place cut side down in prepared pan. Repeat with remaining dough. Cover rolls and let rise until nearly doubled, about 1 hour.
Bake in a preheated 350°F oven for 25 to 30 minutes, until rolls are golden brown. Cool on wire rack for at least 20 minutes.
Combine all frosting ingredients in a large bowl and beat until creamy. Spread over rolls.