To fumble the biscuit is to lose the money (the biscuit) you made or to make unwise investments with the money you already have, i.e. the biscuit. It's also used for fumbling, or botching or bungling, something more generally
The Greatest YouTuber you've never heard of. She only uploads, like, once a year, but it's worth it. She'll bring a smile to your heart and ruin you with puns. She is a true gem of YouTube and deserves WAAAAAAAY more support than she's getting.
Me: Man, TheHumbleNoob's newvideo was awesome!
You: Who?
Me: ...what?