In a large bowl, mix the flour, granulated sugar, baking powder, and salt.
Add the cold butter and work it with your fingertips until the mixture is sandy.
Add the egg and mix until you get large crumbs. Do not compact the dough too much: it must remain crumbly.
Prepare the filling:
In a bowl, work the ricotta with the icing sugar and vanilla extract until smooth.
Add the chocolate chips and stir gently.
Assemble the cake:
Preheat the oven to 180°C (static).
Butter and flour a 24 cm diameter cake pan.
Spread half of the crumbs of dough on the bottom of the pan, compacting them slightly to form the base.
Pour in the ricotta filling and level with a spatula.
Cover the filling with the remaining dough crumbs, spreading them evenly without squeezing too much.
