If I increased my brownie mix by 50% how much should I increase the cooking time by?

[CliffordClaveland]

I'm making this Delia brownie recipe
[https://www.deliaonline.com/recipes/occasions/easter/easter-chocolate-recipes/brazil-nut-brownies].
I've added 50% of everything to the mix how much should I increase the cooking time by, 50%?
TIA

Is it in a shallow tin, like a traybake one? You probably won't need to increase the cooking time by 50 pct, nothing worse than an overbaked brownie!
I make a large mixture (three eggs, two cups of sugar, one cup of flour, 4 0z butter and 4 oz unsweetened chocolate) in a 30x20 cm traybake tin and test it with a wooden skewer every five minutes after 30 mins. Sometimes it's done after 40 mins, sometimes a bit longer.

The key driver is the size of the tin. If it’s as shallow as you’d have use for the original recipe then probably only about 7-10 mins.

Remember brownies -least need less the. You think. Take them out of the oven whilst they still wobble.

always need less than you think

Also if you test it after 30 mins and the skewer comes out with fudgy /sticky crumbs on, it's done.
Only cook it a bit longer if it comes out still wet.

Also my recipe should say 6 oz butter, not 4.

Thanks all, I've used the same size tin as recommended in the recipe. I'll give it an extra 5 minutes and then check regularly using a skewer

Same tin, so deeper?
I'd make a guess of 30 mins as per recipie, plus 10 mins.

Skewer method doesn't work for brownies. You want a slight wobble in the centre when you shake the tin.

you want them out of the oven when they have just stopped wobbling, I use this recipe plus 50% and in a 9x9 tin, but still only do them for 40 mins.....however, I have done the normal recipe and would say the timing is excessive for the recipe as described!

My tests are threefold...

1. just and only just over the wobble, you want a swampish shimmy, not a pannacotta/jelly type wave
2. a small finger poke will feel like a stiff kitchen sponge...one that is really well squeezed out and not at all wet, no dent should show after the poke
3. a tiny (miniscule) amount of rise in the centre and ideally a small crack in a papery looking top. When the brownie is cool, it will be dead flat to slightly sunken in the centre.

if any of the three conditions seem under then i shut the oven door, turn off the heat and give only five minutes more.
Also allow to cool in the tin, do not remove to a rack.

I took them out after the extra 5 minutes and they looked and felt done so I took them out. We've just eaten some and they are fine, definitely done enough.