Grandmom's Cinnamon Rolls

Prepare dough: Heat milk in a saucepan over medium heat until just about to boil, 3 to 4 minutes. Add sugar, shortening, and salt; remove from heat and let cool to lukewarm, about 10 minutes.

While the milk mixture is cooling, sprinkle yeast over water and let sit for 10 minutes.

Pour lukewarm milk mixture into a bowl; add 1 cup flour and beat well. Beat in yeast mixture and egg. Gradually beat in remaining 2 1/2 cups flour. Cover and let rise until doubled in size, about 1 hour. Test by pressing a finger into the dough; a fingerprint should stay.

Preheat the oven to 375 degrees F (190 degrees C). Grease two 9-inch square baking pans.

Prepare filling: Mix sugar, melted butter, and cinnamon together in a bowl.

Turn dough out onto a lightly floured board and divide in half. Roll one piece into a 16x8-inch rectangle. Spread 1/2 of the filling over top. Start at the long edge of the rectangle and roll up as for a jelly roll. Cut into eight 1-inch slices and place cut-sides down into one prepared baking pan. Repeat with remaining rectangle.

Bake in the oven until golden brown, 20 to 25 minutes.

Meanwhile, prepare frosting by mixing confectioners' sugar and water together in a bowl.

Remove rolls from the oven. Transfer to a large serving plate and spread frosting over top.