Imagine a cake good enough to eat upside down. This Victoria Sponge Cake is 100% inspired by Mary Poppins – that lovable British nanny at the heart of  countless quirky adventures – and, yes, it’s that good. The recipe is mentioned in Mary Poppins: 80th Anniversary Collection, which I gave my daughter for Valentine’s Day. A note on these books: P.L. Travers’s collection goes well beyond the parameters of the Disney movie – the floating tea party scene at the heart of the film can be found on page 42, barely cracking the spine of this 1024 page classic. Every night at bedtime we settle into a new chapter, following the 5 Banks children on another adventure. They paint the sky, eat gingerbread stars, hang out with the constellations at a circus in space, and travel the world with a compass – and all that within the first few hundred pages. Mary Poppins not only never explains their adventures once they’re over, she insists she has no idea what the children are talking about. More than buttoned up, Mary Poppins is flat out strict, yet the children always have fun when she’s …