Orange chiffon cake

Heat the conventional oven to 165 °C. Use a 25 cm metal tube pan with a removable base and no non-stick coating. Leave it ungreased. Wash the oranges. Finely grate the peel without the white pith and measure 30 ml zest. Squeeze the fruit, strain and measure 120 ml juice.

Mix the flour, 200 g sugar, baking powder, salt and prepared zest. Add the yolks, oil, measured juice and vanilla. Whisk until smooth.

Whisk the whites with the cream of tartar in a clean, grease-free bowl. At soft peaks, gradually add the remaining 100 g sugar and whisk to stiff peaks. Gently fold the meringue into the batter with a spatula, then transfer to the pan.

Bake for 55 to 60 minutes, until a skewer comes out clean and the top springs back when gently pressed. Immediately invert the pan on its feet or support the central tube, keeping the cake clear of the counter. Cool for 90 minutes, then run a thin knife around the sides, tube and base to release.