A pink cake for Sylvia

I developed this vanilla and raspberry cake when my daughter requested a sugar pink cake for her fifth birthday, and indeed a pink party to match. The kefir makes the sponge whisper-light and the raspberries stud it with pockets of jammy sharpness. A mound of fluffy frosting was another prerequisite – here its sweetness tempered by fresh fruit, which also stains it a suitably Barbie pink. The other trick for lightness in both the sponge and the frosting is seemingly excessive beating.