I've started using cocktail peanuts for baking, because they're inexpensive and always available at our neighborhood Target or CVS. I like cocktail peanuts because they're small, salty, and crunchy, although I do need to spend a some time picking out peanut skins here and there before adding them to whatever I'm baking.
Peanuts are central to the "Peanut Brownie Cookies" from Erin Clarkson at Cloudy Kitchen. By weight, there are more peanuts than the flour plus cocoa powder combined. This recipe is straightforward and doesn't require any chilling time or advance preparation. You cream room temperature butter with sugar and dark brown sugar; add vanilla, an egg, and an egg yolk; mix in a sifted mixture of flour, cocoa powder, baking powder, baking soda, and kosher salt; and stir in peanuts and milk chocolate. I left the peanuts whole and used Ghiradelli milk chocolate chips. I used a #24 scoop to portion out the dough and got 32 cookies from a batch. I sprinkled them with Maldon salt immediately after taking them out of the oven.
Recipe: "Peanut Brownie Cookies" from Erin Clarkson of Cloudy Kitchen.