Today I learned that Congo Bars (at least the version in Nancy Baggett's THE ALL-AMERICAN COOKIE BOOK) are actually a tart.
Here's the BOM for this recipe (baked in a 9x13 pan, allegedly makes 20 but I haven't sliced them yet, and I used more expensive ingredients than shown here):

In other news: sugar is cheap; nuts are expensive.

And eggs are not very expensive (even though state law requires cage-free).

I have never made Congo bars before, at least not of the type Baggett's recipe is (with condensed milk). I'm not entirely sure there is a universally agreed definition of what actually constitutes a Congo bar (although obviously nothing to do with the Congo!) — my memories include things that might today be described as "seven layer bars" and "blondies" under the same rubric. I think the common features are nuts, chocolate chunks, coconut, and something with a caramel-y flavor.
This version, as I said, is basically a tart, with a par-baked pate sucree base and a custard filling, but where the custard has nearly half its weight in added flavorings (nuts and chocolate chips).
I think I've had something similar to this recipe but made with butterscotch chips rather than chocolate? Not sure. There are an awful lot of things in this general category.
@wollman I see the OpenZFS Summit has a new member of the Kitchen Crew!