Gluten-free chocolate almond sponge

Melt the butter with the dark chocolate in the microwave to 45 degrees, the maximum for this sponge.

In the mixer with the paddle (or a food processor), mix the almond powder, the larger amount of caster sugar and the room-temperature whole eggs for four minutes.

Add the melted chocolate and butter at 45 degrees; the mix must not be cold or the chocolate crystallizes. Mix another three to four minutes, then transfer to a clean bowl.

Whip the room-temperature egg whites with half the small amount of sugar, then add the rest in two additions, to a smooth, creamy meringue.

Whisk some of the chocolate mixture into the meringue to break up lumps, then add it all back to the chocolate mixture and mix gently and minimally to keep the air.

Set a 20 by 20 cm flexible frame on a rack, fill with the sponge and level it flat with a spatula.

Bake at 170 degrees for 20 to 25 minutes, depending on the oven, until a knife comes out completely dry.

Cover the still-warm sponge with plastic wrap and refrigerate overnight to keep it moist.