Butter and line the base of a 20cm square cake tin. Heat the oven to 180C/fan 160C/Gas 4. Peel and quarter the pears, then cut out the cores and cut the pears into large pieces. Melt the butter in a pan, add the pears, sugar and spices and cook for 2-3 mins until the pears are just softened and the sauce is syrupy. Leave to cool while you make the cake.