Here's a recipe for macadamia shortbread, but seems like it would be pretty easy to substitute cashews for the macadamias, and load up with the cookies with as many cashews as you want!

Title: Macadamia Shortbread Cookies
Categories: Cookies
Yield: 2 servings

1 c All-purpose flour
3/4 c Confectioners' sugar
1/4 c Cornstarch
1 c Macadamia nuts (4 oz)
3/4 c Unsalted butter; softened

Finely chop the macadamia nuts. Sift flour, sugar and cornstarch. Stir
in nuts. Beat butter in bowl at medium speed until creamy. At low speed,
beat in flour mixture. Using a level tablespoon, shape dough into balls.
Place 2 inches apart on ungreased baking sheets. Flatten each ball with a
fork.
Bake in preheated 300 degree oven 25 to 30 minutes until just lightly
browned around edges. Cool baking sheet on rack 5 minutes. Transfer
cookies to rack to cool.
Variations: Press half a macadamia nut into each cookie before baking.
Sprinkle with rock sugar upon removing cookies from oven. From Family
Circle's "Our Best-ever Cookie Collection".