How much cocoa powder to change normal sponge recipe into chocolate?

[VivaLeBeaver]

I've got a giant cupcake recipe that uses 450g s/r flour. How much of hte flour do I need to swap for cocoa powder. Thanks?

When I make a victoria sponge into a chocolate cake, its (approximately) 6oz flour and 1oz cocoa instead of 7oz flour.

Hope that helps and good luck with the cupcake. I seem to remember reading a thread about those, but can't remember what the issue was with them!

Thanks. I did do a cupcake last year as well and I seem to remember the top cooked quicker than the bottom as they're different sizes. Going to cook them seperatly this time.