Ok, This is how to centre dowel a cake if you feel its very tall/top heavy/ etc
There are multiple ways, but this is how I did it for this specific cake. With a little help from my cakey friends :)
I cut a circle out from MDF with my new jigsaw cutter (yup yup!) It made lots of noise in the front garden…but you didnt really need to know that.
You then counter sink a hole in the centre (not all the way through!) which is the same size as your dowel (in this case 9mm) Put a little dot of wood glue into the hole and put the dowel in. You can always take extra precautions and tap a little ‘tack’ (nail) from underneath the board up into the dowel.
Then get a cake card the same size as your bottom cake, and make a 9mm hole in the middle, make sure you can easily slip it onto the dowel!
Put your cake onto the cake card (securing it with whatever you like to use royal icing/chocolate/buttercream etc) and prepare it for covering.
Cover your cake!
Holding the cake card underneath your cake carefully line up the dowel with the hole you drilled and slip in onto the dowel
Make sure you drill a 9mm hole in the centre of EVERY cake card you use (I remembered, but there were times I almost forgot! lol) then put your usual support dowels into your bottom tier, so support the next one, and so on… When you have finished you should have a VERY sturdy tiered cake :)