Sue Arnold: The day I discovered the cake of good dope

'She had been making inquiries in the village, but no one seemed to know where to get hold of ganja'

This could be the moment for my long-time pen pal Eric to emerge as Britain's new celebrity chef. Eric – he never gave me his last name – first wrote to me about five years ago in response to an article about the astonishing effect that smoking dope has on my failing eyesight. He enclosed a slim volume entitled Cooking With Ganja (by Eric), containing the following poetic prologue: Keep your opium poppy and seed/Give me your hash and a bundle of weed/I'll make us a cake and a nice cup of tea/And you can come fly with me.

Don't worry, Eric's cooking is better than his scanning, especially his chocolate munchy cake, which adds a whole new dimension to that great British tradition of high tea, and indeed to that great French tradition of haute cuisine.

The first munchy cake I ever baked wasn't for me, it was for a mail order. Along with Eric, I'd had a flood of letters from all sorts of people, including two vicars, requesting further information about dope's ophthalmic benefits. "I was most interested to read your article,'' wrote Mrs Bicknell, 83, from Somerset, in wispy, barely decipherable handwriting, "because my eyes are getting very bad. Unfortunately I don't smoke and I wondered if there was an alternative way of taking cannabis preferably in pill or liquid form.''

In Cooking With Ganja, Eric is very precise. THC, he writes, referring to tetrahydrocannabinol, the magic ingredient of cannabis, "isn't soluble in water so steeping marijuana leaves to make tea only produces flavour. A teaspoon of hash oil honey will work if added to boiling water. Alternatively you can use vodka.''

A vision of Mrs Bicknell, 83, with her bad eyes and shaky hands, trying to spoon hash oil honey into boiling vodka made me distinctly uneasy. I advised her to cook with it instead, quoting Eric's handy guide to eating amounts – ie one-sixteenth of an ounce of hash equals eight people mildly stoned or four people very stoned; one-eighth of ganja buds equals 10 people mildly stoned or six people very stoned etc.

Mrs Bicknell wrote back. She had been making inquires in the village, she said, but no-one seemed to know where she could get hold of ganja. She was therefore enclosing a postal order for £5 in the hope that I would... "For heaven's sake, are you mad, mum,'' said my daughter. "You can't go sending spliffs to people you've never met. How d'you know Mrs Bicknell, 83, isn't working for the drugs squad or Special Branch?''

This, don't forget, was long before the present climate of tolerance and Mr Blunkett's decision to reclassify cannabis. This was in the dark ages when police were raiding farmhouses on the Isle of Skye and arresting people for growing marijuana in their window boxes, and magistrates in Merthyr Tydfil were sentencing multiple sclerosis sufferers to six months for possession. "Why don't you bake Mrs Bicknell a space cake,'' suggested my daughter, recently returned from Amsterdam with several slices.

I thumbed through Cooking With Ganja, found the chocolate munchy cake recipe and dispatched said cake to Somerset. A week later Mrs Bicknell wrote back. Was it my imagination or was her handwriting firmer, bolder even. The cake, she said, was delicious. She had invited her friend Vera to join her and they had eaten half of it. She couldn't say precisely if her eyesight had improved because to tell the truth she felt a little tipsy afterwards, as did Vera. But they'd had a wonderful evening talking about the old days well past News at Ten. Best of all, Vera thought her grandson Jason up at the college could get hold of some dope so could I please send her the recipe.

The more I think about Eric, the rosier his future appears to be. TV programmes, roadshows, consultancies, advising Oxbridge dons on high-table menus and Nasa astronauts on space cuisine, guest columnist in British Airways' High Life magazine. The one omission for me is that there are no skunk recipes, skunk being the only form of weed that affects my vision. Then again Black Forest Skunk Gateau lacks a certain plate appeal.