Step 1: Preheat your oven to 400°F (200°C) and line two large baking sheets with parchment paper or silicone mats.
Step 2: In a medium mixing bowl, combine the room temperature cream cheese, finely diced imitation crab, shredded mozzarella, minced garlic, green onions, soy sauce, and sugar. Mix thoroughly until the filling is uniform.
Step 3: On a lightly floured surface, unroll one sheet of puff pastry. Spread half of the crab rangoon mixture evenly over the pastry, leaving a small 1-inch border at the top edge.
Step 4: Carefully roll the pastry sheet into a tight log, starting from the edge closest to you. Use a small amount of the whisked egg to seal the final seam.
Step 5: Using a sharp knife, slice the log into rounds approximately 1 inch thick. Place the pinwheels on the prepared baking sheet, spaced about 2 inches apart.
Step 6: Brush the tops and sides of each pinwheel with the egg wash. Bake for 18-22 minutes, or until the pastry is puffed and golden brown.
Step 7: Allow to cool for 5 minutes before serving with your choice of dipping sauce.