1/2 cup water -- warm
2 cups milk -- lukewarm
1/3 cup sugar
1/3 cup oil
3 teaspoons baking powder
2 teaspoons salt
6 cups flour
4 tablespoons butter
1/2 cup sugar
1 tablespoon cinnamon -- plus one teaspoon
powder sugar frosting
Dissolve yeast in warm water. Stir in milk, 1/3 cup sugar, oil, baking powder, salt, egg and 2-3 cups flour. Beat until smooth. Mix in enough remaining flour to make dough easy to handle. Knead on well-floured board until smooth and elastic. Place in greased bowl. Cover and let rise in warm place until double, about 1 1/2 hours.
Grease 2 13 x 9 x 2' pans. Punch down dough; divide into 2 halves. Roll one half into 12 x 10' rectangle. Spread with half of butter. Mix 1/2 cup sugar and cinnamon; sprinkle half of this mixture over the dough. Roll up, beginning at wide side . Pinch edge of dough to seal.
Cut roll into 12 slices. Place slightly apart in first pan. Wrap pan with heavy duty aluminum foil. Repeat with remaining dough. Refrigerate at least 12 hours but no longer than 48 hours. (To bake immediately, do not wrap. Let rise in warm place until double, about 30 min.)
When ready to bake, preheat oven to 350 degrees. Remove foil from pans. Bake until golden, 30 to 35 min. Frost with powdered sugar frosting while warm.
Powdered Sugar Frosting: Mix 1 cup confectioners' sugar and 1 tablespoon of milk until smooth and of spreading consistency. (Frosts one pan of rolls.)
Variation: Caramel Pecan Icebox Rolls - Before rolling dough into rectangles, heat 1 cup brown sugar (packed) and 1/2 cup butter until melted; remove from heat. Stir in 2 tbsp. light corn syrup. Divide caramel mixture between pans. Sprinkle each pan with 1/2 cup pecan halves. Roll dough, slice, refrigerate and bake as directed. Immediately invert pan on large tray. Let pan remain over rolls 1 minute so caramel drizzles over rolls. Omit Powdered sugar frosting.