All the sweets were bought at the Belarusian pavilion at VDNKh, but they can also be found on marketplaces. I've already found the halva and ate five of them in one sitting. I'm dying, but with a smile on my face :)
To listen while using other apps, switch the player to Picture-in-Picture (PiP) during playback — it keeps playing in a small floating window (the screen stays on).
To listen with the screen fully off, in-browser playback stops by YouTube's design. Open the video in the YouTube app to keep listening where background playback is supported (e.g. with YouTube Premium).
Open in YouTube app