Flourless chocolate wave cake

In a large heatproof bowl combine the chocolate, amaretto, water and oil; set over a saucepan with about three-quarters of an inch of steaming, not boiling, water and melt gently.

Brush the springform pan with oil all the way to the top of the sides, then coat with sugar so the cake can grip and climb.

Separate the eggs while cold, whites into the stand mixer bowl; keep any yolk out of the whites.

Whisk the yolks vigorously into the melted chocolate until the broken mixture emulsifies; whisk in the almond flour until smooth, glossy and thick.

Add the salt to the whites, mix on low to break them up, then medium-high until white and foamy; add the sugar gradually, then briefly on high, to a firm, glossy peak without over-whipping.

Beat in the vanilla after whipping, which loosens slightly over-beaten whites.

Work a first portion of meringue in quickly, then fold in the rest in two additions with a large flexible spatula, scraping the bottom over the top.

Scrape into the pan and dust the surface generously with sugar.

Bake at 350F about 35 minutes, until a cake tester comes out clean (about three minutes more here).

Cool completely in the pan before unmolding; it falls into a wave as it cools.