Preheat oven to 400 degrees. Line a baking sheet with parchment paper.
In a saucepan over medium heat, add in the water, butter, sugar, and salt. Stir to combine.
Let it come up to just a boil. Make sure the butter is completely melted.
Remove from the heat and add in the flour. Stir until a ball forms. The dough will pull away from the pan.
Add the dough into a mixing bowl and let cool for 5 minutes.
Add one egg into the bowl with the dough. Mix on medium until incorporated. Add another egg and mix until incorporated. Repeat always adding one egg at a time and just beating until the egg is mixed in.
Add the dough into a piping bag with a straight tip.
Pipe a mound of dough on the prepared baking sheet. You can do 4 - 5 rows of 3 or 4 depending on the room you have on your baking sheet.
In a small bowl, add in the sugar and cinnamon. Stir to combine.
Immediately generously sprinkle cinnamon and sugar topping on top of each mound of dough.
Place into the preheated oven and bake for 25 minutes until the center is hollow and the shell is browned. Set aside to cool and make filling.
Cinnamon Whipped Cream
In a large mixing bowl, add in the heavy cream and brown sugar. Beat on medium until it becomes thick and soft peaks have formed.
Add the powdered sugar and ground cinnamon into the whipped cream. Beat on high until stiff peaks form.
Add the whipped cream into a piping bag with a #7 wilton piping tip or something similar.
Poke the bottom of the cream puff with the tip of the piping bag. Pipe the whipped cream into the cream puff. Try not to overfill.
Serve immediately and store any leftovers in the fridge.