Spread the refried beans evenly across the bottom of an 8x8 baking dish to form the base layer.
Stir the taco seasoning into the sour cream until fully combined, then spread this mixture over the beans.
Spread the mashed avocados in an even layer on top of the sour cream mixture.
Spoon the salsa over the avocado layer and smooth it gently with the back of a spoon.
Sprinkle the shredded cheese evenly across the salsa.
Scatter the diced tomatoes over the cheese, followed by the sliced black olives.
Cover the dish and chill for at least one hour before serving with tortilla chips.