Preheat oven to 180 degrees C. Grease a 23cm pie dish.
In a large bowl, beat the cream cheese and sugar until smooth. Beat in the eggs one at a time, then stir in the lemon and vanilla essences.
Pour mixture into the prepared pie dish and bake for 35 minutes. Cool cheesecake for 5 minutes. Leave the oven on.
To make the topping: Combine the sour cream and sugar, mixing until smooth. Spread topping evenly over the cheesecake. Return cheesecake to oven for 10 minutes. Cool completely, then top with the lemon curd. Refrigerate before serving.
This is a no-base cheesecake. If you'd like to add a base; process (in a food processor) or crush a 250g packet plain sweet biscuits and mix the crumbs with 60g melted butter. Press this mix into the lined dish and refrigerate while you make the rest of the cheesecake.