I live in Jyugaoka which is only about 15min away from Shibuya by Toyoko line. This little fancy town is known for it’s variety of cake shops and stores full of sweets.
One of the famous place is this complex called “Sweets Forest”. Bunch of famous cake shops are in the complex and people visiting here enjoy the sweets. Not to mention those shops are own by some famous chef so the taste are guranteed.
There are all other small cake shops as well so venturing around the station, you’ll find some nice cafe to grab some of them sweets. Check it out!