Preheat and Prep Pan: Preheat your oven to 350°F. Spray a mini cupcake pan with non-stick spray and set aside.
Cook Pasta: Cook the angel hair pasta to al dente according to the package directions. Drain and transfer it to a large mixing bowl. Allow it to cool slightly.
Mix the Pasta Nests: Add the beaten egg, Parmesan, mozzarella, Italian seasoning, salt, and pepper to the cooled pasta. Stir well until the mixture is fully combined and sticky.
Form the Nests: Spoon 2 to 3 tablespoons of the pasta mixture into each cupcake hole. Press down with your fingers to form a nest shape. Use a shot glass or the back of a wooden spoon handle to create an indent in the center.
Bake the Nests: Place the mini cupcake pan in the oven and bake for 15 to 20 minutes, or until the pasta nests are firm and lightly browned on the bottom.
Heat Meatballs and Sauce: While the nests are baking, heat the pasta sauce and thawed meatballs in a small saucepan over medium heat. Stir occasionally and simmer until fully warmed through.
Cool the Nests: Once the pasta nests are done baking, remove them from the oven and let them cool for about 10 minutes to set and firm up.
Assemble the Appetizers: Place one meatball on top of each cooled pasta nest. Stick a toothpick into each meatball to secure it in place.
Finish and Serve: Drizzle a little extra pasta sauce over each meatball and top with a fresh basil leaf for garnish. Serve warm or at room temperature.