I'm making a 9inch and a 7 inch. Can I leave me cake stacked for 24 hours? I will be using Bubble Straws.

2nd time Stacking Thanks!

I have done it before and the cake was ok.

It should be fine. As long as you support it properly there should be no problem.

I also like refrigerating it because the cakes are firmer when chilled.
HTH

I plan to put 5 straws in. Thanks for the replies.

be more than fine.

When stacking with straws I feel most comfortable with one straw in the center and 6 around the inside edge of the small cake for the sizes you're doing, and I've never had a problem with leaning. Good luck!