To make ahead, cover and chill unbaked lasagna overnight. Let stand at room temperature 30 minutes. Bake, uncovered, as directed. Serve with sour cream and salsa, if desired.
Cook ground beef in a skillet over medium-high heat, stirring until it crumbles and is no longer pink. Drain and set aside.
Stir together ricotta cheese and 1 cup shredded Monterey Jack cheese.
Layer a lightly greased 13- x 9-inch baking dish with 3 egg roll wrappers and one-third each of ground beef, ricotta mixture, and beans; top with 1/2 cup salsa. Repeat layers twice with egg roll wrappers, beef, ricotta mixture, beans, and salsa. Top with remaining 3 egg roll wrappers and 2 cups salsa.
Bake at 350° for 40 minutes. Sprinkle with remaining 3/4 cup Monterey Jack cheese, and bake 10 more minutes or until cheese melts. Let stand 10 minutes before serving. Arrange avocado slices over lasagna.