. Combine yeast and warm water in a bowl. Let sit 5–10 minutes.
Scald milk and let cool.
In a large bowl, cut shortening into flour, sugar, and salt.
Stir in eggs, milk, and yeast mixture until just combined.
Cover dough and refrigerate overnight.
Mix sugar and cinnamon for filling.
Divide dough into 4 parts. Roll into 10x14-inch rectangles.
Sprinkle with cinnamon sugar. Roll into logs and slice ¼-inch thick.
Bake at 350°F for 10 minutes or until lightly golden.
Brown butter : Melt butter in a light-colored pan over medium heat. Watch closely—it will foam, then solids will sink and begin to brown.
When it turns golden and smells nutty, remove from heat and let cool.
Beat powdered sugar, vanilla, and browned butter in a bowl.
Add hot water 1 tablespoon at a time until smooth and spreadable.
Beat with powdered sugar, vanilla, and hot water until smooth.
Ice cookies. Let set before serving.