Combine water, melted butter, warm milk, egg, 1 tablespoon sugar, salt, bread flour and yeast. Mix on low speed.
When all ingredients are mixed well, turn dough out onto a lightly floured surface and roll into a 17x10 inch rectangle
Spread with softened butter. In a small bowl, stir together brown sugar and cinnamon. Sprinkle brown sugar mixture over dough
Roll up dough, beginning with long side. Slice into 8 slices and place into crockpot.
Let rise in a warm place until doubled, about 45 minutes.
COOKING TIP: Before closing the lid on the crockpot, place 2-3 paper towels in between the lid and the top of it. This will help capture any moisture from dripping on top of your dough and will allow it to cook properly.
Place on High for 1 hour and 30 minutes. After 45 minutes has passed from initial cooking time, twist crockpot 180 degrees to help ensure even cooking.
While rolls are "baking", stir together softened butter, confectioners' sugar, vanilla, and milk.
Remove rolls from oven and allow to cool before you top it with frosting.