Adapted from Momofuku's Milk Bar.
I first made these about a month ago and they were so good I made them again. And again and shipped them to my in-laws. And again at my friend's house. Honestly, I don't even remember where I came across them but the idea of a compost cookie just seemed too cool to pass by. The best part is that you can use whatever is on hand in your baking cabinet and you are guaranteed to have an excellent cookie bar. I am listing the ingredients that I think are best but the main thing is to use 1 1/2 cups sweet stuff and 1 1/2 cups salty stuff. Personally, I favor a mix of coconut, butterscotch chips, semi-sweet choc chips, Kashi Go Lean, honey roasted peanuts, pretzels, corn flake crumbs (or chips--something rippled not flat) and almonds.
1 C brown sugar, packed
2/3 C sugar
1 Tbs light corn syrup
1 C butter, unsalted, at room temp (2 sticks)
2 large eggs
2 tsp vanilla
2 C flour
1 tsp baking powder
2 tsp salt
2 Tbs used coffee grounds, dried (can use unbrewed grounds as well) *can use instant coffee granules or espresso granules
1 ½ C sweet mix ins
Recommended: semi-sweet choc chips, butterscotch chips, coconut, peanut butter chips, chopped up candy bar bits, choc-covered raisins, unsalted nuts (slivered almonds are good), cereal (I used some Kashi), left over holiday candy is great!
1 ½ C salty mix ins
Recommended: pretzels, potato chips, salted nuts (honey roasted peanuts are especially good), saltines, Ritz crackers. Avoid strongly flavored items such as Doritos or flavored potato chips as they may lend an off flavor to the cookies. Note: you want to smash up the salty goodies but not to the point where it becomes dust. Avoid using a food processor for this reason.
Preheat oven to 350.
Using a hand mixer or stand mixer, cream together sugars, butter and syrup until light and fluffy, about 3 minutes. Add eggs and vanilla and mix until well blended (mixture will look curdled in the beginning). In a separate bowl, mix dry ingredients. Add dry ingredients to wet ingredients and mix until just combined—do not overmix. Scrape down bowl to make sure everything is well combined.
Add sweet mix ins of your choice and stir to incorporate. Add in salty mix ins and stir to incorporate. Set aside. Butter a 9x13 baking pan or dish and line with parchment. Leave enough parchment to hang over the sides such that you create a sling for the bars. It will help later when you want to pull them out to cool on a cooling rack. Scoop out cookie mixture and spread in an even layer in the pan. Using your hand is the best way to do this. I spray my fingers with a bit of cooking spray to keep everything from sticking. Immediately put pan in the oven and bake for 35-45 minutes or until a knife inserted in the middle comes out clean.
Allow bars to cool for 15 minutes in the pan and then pull sling out and place on a cooling rack until fully cooled. Return bars to baking pan and refrigerate until well chilled. Once chilled, cut bars into desired size. Store in an air-tight container. No need to refrigerate besides, they won't last that long.
*if you want to make these as cookies, you MUST refrigerate the dough for at least 5 hours before baking! Method is the same but cook time will be 9-11 minutes and a 400 degree oven. Exact time will depend on the size of cookies.