Mix ground beef with salt, pepper, breadcrumbs and 1/4 cup parmesan cheese in a bowl and set aside.
Heat a frying pan with a drizzle of olive oil and cook onion until golden brown.
Add the beef mixture to the pan and cook until brown. Remove with a slotted spoon to a paper towel-lined plate to drain.
In another bowl, combine remaining 1/4 cup parmesan, mozzarella, ricotta, egg, salt and pepper; set aside.
Add layer of sauce to the cup bottoms of a greased mini muffin tin.
Cut wonton wrappers with small round cookie cutter so they will fit in the muffin cups.
To each muffin cup, place a wonton over the sauce then some cheese, then meat and then another wonton. Repeat and top with some of the mozzarella.
Bake at 350°F for 20 minutes until golden brown.
Garnish with fresh basil and serve.