Step 1: Prepare the Bean Layer. In a medium bowl, combine the refried beans with the taco seasoning. Mix well until the seasoning is fully incorporated. Spread this mixture evenly as the first layer in a 9x13 inch baking dish or a shallow serving platter.
Step 2: Craft the Creamy Layer. In another medium bowl, beat the softened cream cheese until smooth. Add the sour cream, mayonnaise (if using), garlic powder, and ground cumin. Mix until light, fluffy, and well combined. Spread this mixture carefully over the bean layer.
Step 3: Make the Guacamole. In a separate bowl, mash the ripe avocados with a fork. Add the chopped red onion, minced jalapeño (if using), fresh cilantro, and a generous squeeze of lime juice. Season with salt and pepper to taste. Mix gently to combine. Immediately spread the guacamole over the cream cheese layer.
Step 4: Add the Salsa Layer. Gently spoon the salsa over the guacamole.
Step 5: Sprinkle on the Cheese. Evenly sprinkle the shredded Mexican cheese blend over the salsa layer.
Step 6: Garnish and Chill. Scatter the sliced black olives and chopped green onions over the cheese. Cover the dish tightly with plastic wrap and refrigerate for at least 30 minutes.
Step 7: Serve and Enjoy! Serve with plenty of tortilla chips, vegetable sticks, or toasted pita bread.