An expression that means the same as "it doesn't matter" or "it makes no difference." Symbolizing little change. You bake a pie, you eat a pie, you have no pie.
Dan, "Hey, didn't you just get gas yesterday?"
Jay, "What are you going to do? Bake a pie, eat a pie."
eat a pie or eap is something you say to someone when you don't want to cuss or say, go f*uck yourself.
Joe: Hey I heard that girl Brittany broke a bottle of beer last night on your head! Now I know why you get no girls, cuz your too damn stupid! Bro, I got soooooo many girls!
Jack: Go eat a pie!
Joe: okay...