Take off heat, add flour while stirring, make sure there are no clumps
Allow mixture to cool until warm (30-60min)
Using a hand mixer, add eggs one at a time until fully incorporated
Pour mixture onto a baking sheet in a rectangular pattern
Bake at 400 degrees for 45min (second rack from the top)
Bake at 350 degrees for 10min, should be golden brown and puffed
Remove and cool to room temperature
Add powdered sugar and water (or heavy whipping cream) to a small bowl and thoroughly mix; 1 part liquid to 10 parts powdered sugar (balance ratio as needed)
Drizzle frosting over the puffed pastry
Storage
Store in a container or wrap in foil
If frosting used water then can store on the counter, if frosting used heavy whipping cream then store in the refrigerator