I am making a two tier topsy turvy for 23 people. What size cakes should I start with for the two tiers? I really like the tapered look and planning on each tier being about 4.5" inches prior the the angled cuts. Thanks for your help!
Since a regular 8"x4" round serves 24, really, anything bigger and you'd be fine.
Are you going to carve it or were you going to back the layers in graduating sizes? If you go 6/8, then you can back a 4", 5" and 6" layers for the top tier and back a 6", 7" and 8" layer for the bottom tier. Now that might seem small because it's more like a 4" and a 6" (using the bottom of the tapered tier for the sizing). So if you went up to an 8/10, there will be some cake left over probably.
Then you could bake a 6, 7", and 8" tier for the top, and an 8", 9" and 10" tier for the bottom.
I made my first (and only) topsy turvy for my birthday 2 years ago (it's in my photos) and I did the tapered tiers, and it with a 6/8/10 tapered as I described above. It was awkward to cut, because it was tapered, but I was able to feed 50-60 with it. Not sure if a more experienced cutter would have done better.
I was planning on carving, it seems a bit easier to ensure proper baking for each cake. Going between staring with a 9"&6" or 8"&5" (four 1.25-1.5" cakes in each layer)... I seems to always overshoot with amounts, trying to avoid it this time.
I think you should go 5" or more on the tiers. TT cakes look best when they are nice and tall. I make mine just about 6" tall. A 6" tall TT tiered carved down will yield the same amount of cake servings as a normal tier of the same size as your top diameter.
That is... if you take three 8" layers (technically 30 servings).. stack them and taper them to 6" at the bottom... carve the top angle, you are left with at least 20 servings. I'd do a 5" over and 8" for the servings you need.
That's really helpful, thank you! Just a quick question on support, will 6" of cake/buttercream be OK unsupported or should I dowel at 3" or so? I always thought 4" was max, but I broke this rule last week and it seemed to hold up OK, not sure if I just got lucky...
6" will be fine. I do it all the time. Most of my cakes are 4.75-5" tall anyway. you will want to support your top tier of couse, but the bottom tier will be perfectly fine without a board 1/2 way up.
I can't thank you enough!
No problem at all!