Mix together all ingredients in a large bowl until well combined.
Refrigerate dough for at least a half hour. This will help it firm up before using.
Using a spoon, scoop dough into balls and place on an ungreased baking sheet.
Bake 10 to 12 minutes at 350 F.
You can use several types of add-ins, but keep the total to between 3/4 cup and 1 cup. If you want to make more than one type of cookie, divide the dough before stirring in any additions, and scale down the mix-in quantities accordingly.
Many cake mixes and candy mix-ins contain dairy, so if you need to keep your cookies pareve, make sure to check labels to ensure they are dairy-free.
For cookie bars, place batter in an ungreased 8×10 inch glass pan. Bake at 350 F (180 C) for 18 to 22 minutes or until a toothpick inserted comes out clean. Cool before cutting.