140g butter, melted, plus extra butter for the tin
100g self-raising flour
175g caster sugar
175g porridge oats
1 egg, beaten
100g glace cherries, halved
50g dark chocolate
Heat oven to 180C/160C fan/gas 4. Butter and line the base and sides of a 22cm square cake tin: cut 2 strips of baking parchment the width of the tin and longer than the base and sides, and fit into the tin each way and up the sides. This will make lifting it out easier.
Mix together the flour, sugar and oats in a bowl. Add the egg, melted butter and cherries, and mix well. Tip into the tin and spread evenly with a fork.
Bake for 20-25 mins until golden brown. Cool in the tin for 10 mins, then carefully lift out using the paper and place on a board. Mark, but don’t cut, 4 lines each way to make 16 squares. Melt the chocolate in the microwave for 1 min, then drizzle over the squares. When the chocolate has set, cut the squares down the marked lines.