Yeasted cake, where am I going wrong?

[BranchingOut]

I am keen to make a yeast based cake. The recipe asked for half a teaspoon of fast action yeast, 500g flour, some sugar, butter rubbed in and warm milk. I didn't have enough plain flour so I substituted strong bread flour.

It said put in a warm place, so I chose a sunny windowsill but nothing much happened in the way of rising. Should I rise it in an oven turned on v low?

I baked it and it was brown on the outside, but utterly soggy on the inside.

Where was my mistake? Should I use a whole sachet of yeast?
Thanks.

Was the yeast the type that goes straight into the mix or the type that should be activated in warm milk/water first? Half a teaspoon doesn't sound very much for 500g of flour. Maybe try the whole sachet next time.

It doesn't sound like very much yeast tbh, I would add more.

I agree very little yeast for that amount of flour, for 500gm I would use a 7 GM sachet and a half a sachet I also leave to double in the airing cupboard :)
Good luck for the next time round.

Thanks, I tried it again and it was still a disaster, even using the whole sachet of yeast.

However, I now realise the yeast is out of date - could that be the problem?

Yes. Out of date yeast is going to be useless. Try again with some new yeast