a piece of cake

[At a cram school]
Wow you don't look nervous at all the day before Eiken!
Nope as I have been studying for this test ALL MY LIFE!!!!
It is going to be a piece of cake!
Good luck!
[塾にて]
英検試験前日なのに、落ち着いてるね〜!
んん。このテストに自分の人生をかけてきたからね!
明日は朝飯前だよ!
頑張って!