Generally speaking what are the fat/sugar/flour ratios for brownies and blondies?

[soupyspoon]

I cant fathom a lot of different recipes and work out if they would have a chance of working.

I dont really understand it for cakes. Im amazed on Bake Off when the contestants are given a task and they seem to intuitively know what ratios of fat/sugar/flour makes up this or that sponge or this or that pastry

Anyway, when looking at different recipes for brownies and blondies for example, what is the general gist of the ratio do you think

Some Ive seen are equal butter, sugar, flour weights

Some seem to have very little butter or very little sugar in terms of the ratios

I dont know how to work out a good recipe or not

Also if melted chocolate is used, does that count as a fat?

Also what is the contribution of eggs? Raising effect or thickening or fat?

Anyone?

I wouldn't be trying to figure it out with brownies especially as there are many different types of brownie texture so recipes will vary hugely. If you fudgey ones for example google a recipe specific to them. Pick reliable sites, pick a US site if you are there and a UK site for here as ingredients differ and don't get involved in the whole cups thing unless you are in US. Scales is much more accurate and consistent.

For other baking stuff it's a bit of experience and learned knowledge, for example basic scones are quarter fat to flour, pastry is half fat to flour, victoria sponge is 1 egg to 50g/2ozs butter/sugar/flour, fatless whisked sponge is equal eggs to ounces of sugar flour i.e. 3 eggs, 3 ozs sugar, 3 ozs flour. This is years of baking knowledge but a good book on the theory of baking is handy if you want to know how ingredients interact with each other.