Blondie problems

[Chuffingchuff]

Hello, wonder if anyone can help me. I am trying to make blondies and I am using the following recipe:
115g butter
400g light soft brown sugar
250g plain flour
1 teaspoon baking powder
1/2 teaspoon salt
2 eggs
Vanilla extract

I bake it low on 120°c in a fan oven for 45 minutes, any higher and quicker just burns the top. I think there is an issue with the oven with temperature!

The problem I am having is that my blondies are coming out beautiful on the edges, really thick and chewy, but the middle is like a hard lid with the inside sunk right down to half the height with a gap in between. Why would this keep happening? I have tried 3 times now and the same thing. Do I need to bake it longer? Higher? Change the recipe? It's so frustrating!! Any advice would be greatly appreciated!

Bumping for you OP.

Two suggestions from me though based on, er, never ever having made blondies.

1. Could it be too much baking powder so rising too high then sinking again?

2. What if you cover it with tin foil so it doesn't burn?

that seems a high sugar to butter ratio to me, so the sugar is likely to burn and you won't have much substance hence the sinking.

45 minutes also seems too long for baking anything you want to be squidgy, I do brownies for 25 minutes only.

What's the method for that recipe?

@msmighty its mix the sugar and butter until crumbly, add eggs and vanilla until smooth, then add dry ingredients and mix until combined, out in pan. I only bake for 45 mins as I think theres a problem with my oven temp being too high so I bake low and slow. The edges come out lovely and chewy.

Also I have tried to cover with foil but it doesnt cook the top properly then, unless I cover half way through and it still sinks.

You need to add chocolate!

Have you tried a different recipe? Looking online the ingredients and quantities are different. Maybe it's just a crap recipe.

i think it is a duff recipe in that case, as firstimpressions said, online most of the recipes are very different, I'd look for something else tbh.

Thanks everyone. Yes I have been looking around and tried a couple of other recipes. Maybe I should just keep trying.