Preheat oven to 170c.
Line and grease a 24cm round spring form tin, crush the biscuits until a fine crumb. Place the biscuit crumb into a bowl and melt the butter. Mix the butter with the crushed biscuits until well combined, then press this into the prepared lined tin.
In a blender, food processor or with a whisk, combine the eggs, sugar, cream, yogurt orange zest and vanilla. Blend until smooth, then add the corn flour and pinch of salt and blend again.
Pour the filling on top of your crust and bake for 35 minutes until firm to touch but still a little wobbly.
Allow to cool for 2-3 hours in the fridge before releasing it from the tin.
For the oranges heat the juice and sugar in a saucepan or frypan until boiling.
Turn off the heat and add in the oranges. Leave the orange in the juice until they are cool. Remove the oranges and set them aside.
Bring the juice back to the boil and reduce to a simmer until slightly syrupy. Serve the syrup with the oranges and cheesecake.