Spread out the pine nuts on a baking tray then toast them for 10 minutes in the preheated oven or until just golden. Check often to avoid burning. Remove from the oven, cool and set aside.
Increase the oven to 180 degrees C. Grease and flour a 23 or 25cm round cake tin.
Beat the egg and sugar in a bowl with a handheld electric mixer for about 3 minutes. Add the melted butter and beat for 2 minutes longer. Add to the bowl, zest and juice of orange and vanilla extract then beat for 1 minute.
Add all the other dry ingredients (flour, salt, baking powder) and stir well. Pour the milk to make a looser cake mixture. Finally, add half of the toasted pine nuts and mix well.
Transfer the mixture to the prepared tin and smooth the top. Sprinkle the remaining pine nuts on top of the cake.
Bake in the preheated oven for about 30 minutes or until a skewer inserted into the centre comes out clean. Remove from oven, cool on a rack and serve.