Hi
@Joanna
Welcome to the site.
Aww, I'm sorry that you're having trouble with the cakes and hopefully I'll be able to help some. The basic recipe you mentioned is most probably a Victoria Sponge Recipe which is very versatile and easy to bake with.
However, as you said the cakes have risen in the middle and burnt which suggests to me that the temperature is way too high for the cakes. (It can also be caused by too much raising agent or the tins being overfilled with batter).
I'm not sure how deep the tins are that you have bought but when I bake a 6 x 3 inch Victoria in my fan-assisted oven I bake it at 150°C on shelf two, (because I have a large capacity oven) for around 55 minutes. If you have a small oven I would bake it on the middle shelf.
Generally, the deeper the cake tin the lower the temperature you would bake it at maybe 150 or 160°C would be fine, I would only bake a
Victoria Sandwich at about 170/175°C on my middle shelf but that's because it's only about an inch deep when baked and bakes much quicker. Anything that's deep bake on lower for longer, that way you get a more even bake.
180°C is probably for a conventional oven with no fan as when you have a fan assisted you have to reduce the temp down by 10-20°C to compensate for the air being circulated by the fan.
To ensure the cake is baked in the middle insert a knife or
skewer into the centre of it. If the knife/skewer comes out with a gooey cake mixture on it the cake isn't baked in the middle. If it has a little crumb on it it's done.
Another way to test a cake when it comes out is to push your finger lightly and very quickly onto the cake (be careful the cake is hot). If your fingerprint springs back the cake is baked if it doesn't it needs to continue baking. Another way to test if the cake is done is by sound, if you lightly push quickly on the cake (again be careful because it's hot) it will sort of make a soft hiss sound at you like it's crispy. Sounds weird but works all the time when I make Madeira cakes.
Anyway, hope this helps, I'm really glad that you're testing your cake tins and recipe (you'd be surprised at how many people don't).
If you need anything else then let me know.
You're doing great and well done for thinking to reduce the temp down.