In a largr skillet, cook ground turkey and jalapeno, if using, with half of the taco seasoning mix until turkey is no longer pink; remove from heat and set aside.
Meanwhile, spread cream cheese into the bottom of a 13x9x2-inch baking dish. Spread refried beans over cream cheese layer. Stir the lemon juice into the mashed avocado and spread over refried bean layer. In a small bowl, stir together sour cream, mayonnaise, and remaining taco seasoning mix. Spread this sour cream mixture on top of the avocado layer. Top with ground turkey mixture and sprinkle top with cheese.
Bake, uncovered, in a 325 oven about 25 minutes or until heated through and cheese is evenly melted. Top with green onions, shredded spinach, and chopped tomato. Serve with vegetable dippers and/or baked tortilla chips.