When I’m feeling playful, I make thumbprint cookies. I remember making batches of them at school, and taking great pleasure in sticking my thumb into the middle to create a home for jam, curd or chocolate spread. These lemon-and-thyme versions feel a tad more grown up, though, with fresh thyme worked through the dough for an aromatic twist. I’ve made a very zingy lemon curd to dollop into the middle, but shop-bought would work just as well.