Line a large baking pan with parchment paper and set aside.
Unfold the puff pastry sheet onto a lightly floured surface.
In a small bowl, combine butter, brown sugar, and 1 teaspoon of cinnamon.
Spread the cinnamon butter mixture on half of the unrolled pastry sheet. Fold the other half over the half containing the filling.
Roll out the pastry sheet into a rectangle of about 1/8 of an inch thickness, pressing the cinnamon butter mixture into the pastry.
Using a sharp knife or pizza cutter, cut the pastry into 1-inch wide strips
Working gently, twist and tie the strips to make the knots.
Place on the prepared baking pan and pop into the fridge for 30 minutes.
Spray the Air Fryer basket lightly with cooking spray and preheat to 350 degrees F.
In a medium shallow bowl, combine granulated sugar with the remaining teaspoon of cinnamon to make the cinnamon sugar. Set aside.
In a small bowl, lightly beat the egg with 1 tablespoon of water to make the egg wash.
Brush pastry knots with egg wash.
Transfer pastry knots to the Air fryer and cook for 8-10 minutes, until puffed up and golden brown.
When done, roll pastry knots in cinnamon sugar while still hot to completely coat.
Serve warm.