Preheat the oven to 400 degrees F. Line a large baking sheet with parchment paper and set another piece out on the counter.
Lay both sheets of puff pastry on the additional parchment. Roll them slightly to remove the seams. Then mix 2 tablespoons of sugar with 1 teaspoon of cinnamon and sprinkle over the entire surface of one puff pastry square. Cover the puff pastry sheet with the second puff pastry square and line up the corners.
Using a sharp knife or pizza cutter, cut through both sheets dividing the square into 4 equal sections, leaving a 1 1/2- to 2-inch area in the very middle that is uncut. (This will hold the sunburst together.) Now cut each quarter section into 5 equal strips, again leaving the untouched section in the middle. Trim the corners off the square to round it out. Carefully move the sunburst to the prepared baking sheet. (The parchment you cut on may have slashes in it.)
Gently pick up one strip and twist it into a rope. Be careful not to pull too hard, or it will break off. Repeat, twisting each section in the same direction all the way around the circle. Then gently pull each rope to lengthen them. Beat the egg and water together to create "egg wash" then brush it over the top. Sprinkle with the remaining sugar and bake for 20+ minutes, until puffy and golden-brown. Serve warm or at room temperature.
Notes
NOTES: For an savory version, skip the cinnamon and sugar and substitute 2-3 tablespoons of store-bought pesto instead. Follow the instructions as mentioned otherwise. I used roasted red pepper pesto for the savory Sunburst Pull Apart Bread in this post.