I bought a package of Almond Roca cookie bar mix, and the bottom layer
was a combo of flour, sugar, baking soda, salt, and a bunch of stuff
that probably isn't needed. It's sort of a shortbread/sugar cookie
base which you mix with softened butter and press into the pan. It
calls for no liquid. The next step is to pour hot caramel (brown sugar
cooked with butter) over the dough and bake it for 15-20 minutes until
all of the caramel is bubbly and essentially thick soft-ball stage.

Here's my question:

If I wanted to make my own cookie base, what recipe could I use? It
needs to be a dry base that when mixed with butter can be pressed into
a pan and act as the "base dough" for the cookie bars, and will not
require a long cooking time.

TIA for any insight!

-L.