Orange angel food cake with passion fruit syrup recipe

Preheat the oven to gas 4, 180°C, fan 160°C. Sift the flour and icing sugar into a bowl. In a separate bowl, beat the egg whites with an electric whisk for 2-3 mins on high until white, fluffy and doubled in volume. Add the cream of tartar, orange zest and vanilla, and whisk for 1-2 mins until soft peaks form.
Whisk 140g caster sugar into the egg whites, 1 tbsp at a time, until stiff and glossy. Sift over a third of the flour mixture and fold in gently until just combined. Repeat with the remaining flour mixture, folding in gently.
Pour the mixture into a 2-2.5ltr bundt tin and smooth the top. Run a knife through the centre of the batter to remove large air pockets, then smooth again. Bake for 45 mins until lightly golden and a skewer inserted in the centre comes out clean. Invert the cake onto a wire rack immediately and leave to cool in the tin. To turn out, you may need to run a palette knife down the inner and outer sides to gently separate the cake from the base of the tin.
Meanwhile, put the remaining caster sugar in a pan with the passion fruit pulp. Dissolve the sugar over a low heat, then bring to a simmer; cook for 2 mins until slightly thickened. Set aside to cool for 20 mins until thick and pourable.
Meanwhile, put the icing ingredients in a bowl and whisk with an electric whisk for 2-3 mins until it just holds its shape. Spoon and swirl over the cooled cake. Drizzle the syrup over to serve.