Known in England since about 1965, we're obliged to our correspondent Trish Johnston for pointing out that they may be derived from "the rice crispies version which I am familiar with, the Chocolate Crackle, originated in Australia. It was featured in The Australian Women's Weekly in 1937."
The original source of this receipt isn't known. Can you help? raise an issue on GitHubCornflake Cakes - Makes 12
2oz Butter
2 oz Milk Chocolate
4 oz Corn Flakes
2 tbsps Golden Syrup
Melt the butter, syrup and chocolate in a bowl for 1 minute over boiling water, stir in the corn flakes and spoon into 12 small paper cases. Chill to set.

Cornflake Cakes
Image: www.dovesfarm.co.uk