Mimosa Cake with Pineapple

Start with the eggs and sugar for the sponge. Whisking them until "light and creamy" isn't decoration talk — you're beating air into the mixture mechanically, because there's no other raising agent here, no baking powder in the list. That foam is the only thing holding the cake up in the oven. If you stop whisking too early, the batter stays dense and wet-looking even after baking; if you fold the flour in badly — stirring hard instead of folding from the bottom up — you knock that air straight back out, and the sponge comes out flat and tight-crumbed. The gentle fold is there specifically to protect the bubbles you just worked for.

Potato starch alongside the plain flour is the reason this sponge stays soft rather than bready. Starch has no gluten to speak of, so it dilutes the flour's gluten-forming power and gives you a crumb that's light and a little short, closer to a Victoria sponge than a dense loaf cake. If you don't have potato starch, cornflour does the same diluting job — any starch with no flavour of its own and no gluten, that's the real criterion, not the brand on the box.

For an ordinary British kitchen, "conventional setting" at 170°C means don't use the fan if your oven has one, because a fan dries the surface of a sponge faster than the inside cooks, and you get a tough skin over a pale middle. The 50 minutes is a floor, not a verdict — a skewer coming out clean, or the sponge springing back when you press it lightly, tells you it's actually done; a domestic oven running a bit hot or cold will shift that number around by ten minutes either way, and that's normal, not a failure.

The custard stage is where most mimosa cakes go wrong, and it comes down to one thing: pouring the hot milk into the yolks "in a thin stream" while you keep stirring. That's tempering — bringing the yolks up to heat gradually so the proteins set slowly into a smooth cream, instead of hitting a wall of heat all at once and scrambling. Some believe a water bath is the only safe way to cook egg yolks without curdling them; no, because tempering plus a gentle hand over the heat does the same protecting job without an extra pan to wash. Bringing the mixture fully to the boil afterwards is non-negotiable for the flour reason already mentioned — taste it afterwards and you'll notice it's clean, not pasty.

The double cream has one job: whipped to stiff peaks, it carries air into the custard the way the eggs carried air into the sponge. Whip it too far, past stiff into grainy and separating, and when you fold it into the custard the cream breaks rather than lightens it — so stop the moment it holds a peak that just about stands, don't chase extra firmness. Any cream with enough fat to whip stiff will do this job; in the UK that's double cream itself, no substitute needed, since it's sold everywhere and this is exactly what it's for.

Tinned pineapple earns its place for practical reasons as much as flavour — fresh pineapple contains an enzyme, bromelain, that breaks down proteins and would slowly turn your cream watery and thin over the two hours it needs to chill; the tinning process cooks that enzyme to death, which is why tinned is specified and not a swap you should casually reverse. The syrup from the tin, or straight pineapple juice, becomes your soaking liquid for the thin sponge layers — soak lightly, a brush or spoon pass is enough, because three thin layers plus sauce can slump into a soggy stack if you drown them, and there's no outer sponge wall here to hold a wet filling in.

The final move — grating or cubing the second sponge and scattering it over the cream-covered cake — is the whole point of baking two sponges in the first place. You're not wasting a cake, you're manufacturing crumbs on purpose, in a texture a food processor or a fork can't quite replicate as well as a knife cutting clean 1cm cubes by hand. A kazan or a show-off piping tip has no role here; a wide bowl, a palette knife and a chopping board are the entire equipment list, and that's honestly all a flat kitchen needs for this one. This is a cake for six, and the long chill at the end is the last patience test — rush it and you're serving warm custard with crumbs on top rather than a cake that holds its shape when you cut into it.