1. Stir together first 5 ingredients, 1/2 teaspoon salt, and 1/2 teaspoon black pepper. Set aside.
2. Drain artichoke hearts, reserving oil, and coarsely chop. Stir together artichoke, reserved oil, avocado, green onions, and remaining 1/2 teaspoon salt and 1/2 teaspoon pepper. Set aside.
3. Melt butter in a medium saucepan over medium-high heat; add garlic, and saute 1 minute. Add flour, whisking until blended; cook, whisking constantly, 1 minute. Gradually whisk in whipping cream. Cook, whisking constantly, 3 to 4 minutes or until thickened and bubbly. Stir in 1 cup Parmesan cheese.
4. Layer one-third of noodles, half of ricotta cheese mixture, 1/2 cup cream sauce, and half of avocado mixture into a 13- x 9-inch baking dish coated with cooking spray. Repeat layers once, ending with remaining noodles and remaining cream sauce. Sprinkle with remaining 1/2 cup Parmesan cheese.
5. Bake, covered, at 400° for 40 minutes. Uncover and bake 5 more minutes or until lightly browned. Let stand 15 minutes.

*Large avocados are recommended for this recipe. A large avocado averages about 8 ounces. If using smaller or larger size avocados adjust the quantity accordingly.