3 ounces dark (at least 70%) chocolate
1 cup lightly packed brown sugar
1/2 teaspoon vanilla extract
1/2 cup plain flour
1/2 cup broken walnuts
Preheat oven to 350 (180 on my cooker)
Line an 8" baking tray with greaseproof paper
Melt together the butter and chocolate
Whizz everything except the walnuts together in a food processor.
Fold in the walnuts.
Pour into baking tray and cook for a scant 20 minutes: it should still be slightly gooey in the middle.
Permit your mother to escape into the sunshine with a good book for a little while: her head hurts from all those parabolas.
Good book: "Angels and Men" by Catherine Fox
That's "Angels" not "Angles".