Maths at A level meant cake. Latin was tea and biscuits. A heavy arsenal was needed to convince a class of angsty teenagers to recite conjugations and grapple with statistics. In maths class we had a cake rota – every Wednesday someone brought smarties cookies or a cake made by a patient mother. One week Mr Priday even brought a cooler with fat wedges of icecream cake. But in Latin tea was obligatory in every lesson. Mrs D must have drunk ten cups a day. There was also a tin of crumpled digestive biscuits for dipping.
But I liked bringing biscuits. I liked getting out my biscuit bible on Tuesday nights and choosing a recipe from the Butter-rich, Jam-packed, Chocolate-covered Cookie Book. I liked the unashamedly sugary American recipes. In the end I won the Latin prize for my dedication to biscuits. (She said she couldn’t decide, we were all great at Latin. I felt like a fraud.)
And this particular recipe has stayed in my head ever since, for its beautiful ratio of ingredients. (I did like maths too!) Especially with the American measurements: 1 stick butter + 1 cup flour + 2/3 cup sugar + 1/3 cup cocoa. As soon as you learn to recognise the rough size of a cup measure, you can make it anywhere, without scales. You just need a bowl, a baking tray and an oven. And it served me well on my travels; chocolate squares of thank-you and sorry.
Mathematical chocolate shortbread
100g butter (1 stick)
250g flour (1 cup)
130g caster sugar (2/3 cup)
80g unsweetened cocoa (1/3 cup)
(If you don’t know what a cup looks like, measure 250ml water and tip it into different mugs until you find one that suits. Makes life easier.)
Chop the (cold) butter into rough dice. Stir the flour, sugar and cocoa together. Either pulse everything in a food processor or gently rub the butter into the dry ingredients with your fingertips. Take care not to overwork the mixture. It doesn’t need to be a solid dough, but rather a pile of dry breadcrumbs. Tip the mixture into a buttered square tin (about 20x20cm) and press down firmly.
Bake in a hot oven (about 180C) for 15-20 minutes. It will be cooked when the house starts to smell like melted chocolate and the shortbread is just cracked on top. Cut into squares as soon as it comes out of the oven (it might be too hard later) but leave in the tin to cool.