Preheat the oven to 175°C. Line the base of a 20cm springform pan with baking paper.
In a large bowl, beat the eggs and sugar.
Add the ricotta and lemon zest and mix well.
Stir in the cornstarch and add the chocolate chips.
Pour the mixture into the springform pan and bake for 75 minutes.
Leave to cool completely.
Dust with icing sugar and serve.
