A cream cheese and cake mix preparation.
I can’t find anything suggesting there’s a California origin to these; there are references in pay-per-view sources from the late 1950s, and Google searches have people attributing them to the mid 1960s, but nobody has an explanation for the name. I can tell you, however, that similar recipes are often described as cream cheese squares.
From a box sold in Martinez, California.
California Squares
Crust–mix together:
1 pkg. yellow cake mix
1 cube melted butter
1 egg
1 c. pecans or walnuts (chopped)
Flatten out in cookie pan with sides.
Filling–mix together:
1 8-oz. pkg. softened cream cheese
2 eggs (beaten)
1 tsp. vanilla
Pour over top and bake at 350, 30-35 minutes.
Pan: 15-1/2″ x 10-1/2″ x 3/4″ pan.
You forgot to add the powdered sugar to your reprint of the recipe. The original has it listed though.