In a bowl, mix salt, flour, and yeast together.
Warm milk, add butter and sugar and stir to combine.
Slowly add liquid to dry ingredients, and mix until combined.
Add egg, and mix until fully incorporated, the dough should be soft.
One hour later, cover the bowl and let the dough rise.
The dough should be rolled into an 8-inch square on a floured surface.
Mix melted butter, brown sugar, walnuts, and cinnamon.
Spread mixture over dough, leaving a ½-inch border.
Roll the dough tightly, and cut into 10 even slices.
Place slices in greased 10-inch cake pans.
Allow rolls to rise in a warm place for 20 minutes, covered.
Preheat the oven to 375°F, and bake for 20 minutes.
Whisk cream, sugar, milk, and vanilla until smooth.
Rolls should be served warm with frosting spread over them.