Tarquin Winot pronounces on a variety of dishes as he travels south through France, though cakes as such aren't mentioned as far as I recall. He provides a recipe for Queen of Puddings, admits to an embarrassment of scones at Fortnum's, but otherwise leaves us craving some sweetness - in more ways than one!
He does recall a meal with his mother at La Coupole in Paris at which they shared a lemon tart - "and this is something for which I am not going to be bothered to give a recipe: simply purchase the relevant pudding from someone authoritative", he says.
To make this classic tart, which Tarquin includes in a menu as "intended to give a sense of warmth and sunlight ...", I've gone back to Jane Grigson's Fruit Book and the recipe I've used countless times.
Mrs. Grigson introduces it with a line or two which might have been Tarquin's own: "The best lemon tart I know. The recipe comes from our young doctor at Trôo, whose governess used to make it regularly. What a happy childhood! The three children devoted to each other, kindly if remote parents and a gastronomic governess. Never, it seems, did she give them prunes and rice pudding."
Lacking time and being a couple of lemons short of the required number, I've made the simple, unadorned version. I expect Tarquin would approve.