Place frozen meatballs in a large, microwave-safe casserole dish. Cover and microwave on high for about 5-6 minutes, stirring every 2 minutes until heated through.
For each wonton, place about one teaspoon of the cream cheese mixture in the center of a wonton wrapper. Top with a cooked meatball and moisten the edges with beaten egg.
Bring two corners up to meet of the top of the meatball and press to seal the corners together. Then, bring up the other two corners, pinch together at the top and press the seams together.
Bake at 400 degrees for 10-12 minutes, until crispy and golden.
Notes
The wonton wrappers dry out very quickly so be sure to keep the package and the prepared wontons covered with plastic wrap.