Hi everyone!

I need some advise. It's my first time stacking a 3 tier cake - with a dummy base and all 3 cakes in buttercream. Do I need to insert a dowel through all 3 cakes? And add skewers through them? Need to have the cake ready for this Saturday. Any advise would be deeply appreciated!

This is the idea with the bottom tier as a dummy - everything in buttercream

You don't need a central dowel at all, you're basically making a two-tiered cake with a styrofoam base. Just put dowels in the middle tier to support the top tier. You do want to make sure that the middle tier is secure on the bottom, but if you just stack it like a normal buttercream cake would be stacked then refrigerate it normally it should be fine. If you're worried about it shifting you could put a dowel through the whole thing, but it isn't necessary.