preheat the oven to 375°
sprinkle flour on a clean counter
roll the puff pastry sheets out together, end to end to make to make one long rectangle
brush the melted butter on top of the puff pastry
in a small bowl mix the sugar, cinnamon, and salt together
sprinkle it over the melted butter
roll up from one of the short ends to make a big log
cut the log into 12 equal pieces
arrange the pieces in the prepared pan
chill for 30 minutes in the fridge
remove from the fridge
beat the egg and vanilla extract together to make an egg wash
brush the top of the cinnamon rolls
bake the cinnamon rolls in the preheated oven for 20-25 minutes or until puffed and golden brown
if using the optional icing, mix powdered sugar and just enought milk together and drizzle over the top of the cinnamon rolls after they're finished baking