This isn't necessarily cake related, but you can print out coupons at
Recipes & Cookbooks - Cooking Recipes from Betty Crocker from BettyCrocker.Com for Betty Crocker products. You do have to sign up for the coupons but it's free; and you can also use your account to log onto
Pillsbury.com and print coupons from there too. Also
VeryBestBaking - NESTLE - Welcome usually have coupons for chocolate chips or evaporated milk.