To prepare the ricotta for the ricotta and crostata (tart) filling, drain in a colander for a few hours to overnight.
In a food processor (with the metal blade inserted): Process the flour, butter and salt until the texture resembles fine breadcrumbs. Add the icing sugar, eggs, vanilla bean and lemon zest. Mix until the dough just starts to come together.
Alternatively, by hand: Combine the flour, butter and salt in a bowl. Use your fingertips to rub the butter into the flour until the texture resembles fine breadcrumbs. Add the icing sugar, eggs, vanilla bean and lemon zest. Mix by hand until the dough just starts to come together.
Note: 00 is a powder-fine Italian type of flour. It is made from soft wheat varieties, and is frequently used in Italian desserts and pastas. 00 flour is available in most supermarkets, Italian food stores and gourmet delicatessens.
Tip: If mixing by hand, remove the butter 20 minutes beforehand to soften slightly.
Turn the pastry onto a clean, lightly floured work surface and lightly knead to bring together. Gather the dough with your hands to form a ball. Wrap in plastic wrap (cling film) and refrigerate for 1 hour
Preheat the oven to 170°C conventional oven/150°C fan forced (338° Fahrenheit/Gas 3).
Meanwhile to make the ricotta and chocolate crostata (tart) filling, use a spoon to mix the ricotta, caster sugar, orange zest and vanilla bean (or vanilla bean paste) until smooth. Use an electric mixer, if required, to achieve a smooth consistency. Add the dark chocolate bits to the filling.
Grease a 24cm round, loose-bottom metal tart tin with butter. Turn the dough onto a large sheet of non-stick baking paper. Use a rolling pin to roll out the dough to a thickness of 7-8mm. It should be large enough to fit the base and sides of the tin (allowing approximately 4cm overhang). Flour the rolling pin well and gently roll up the sweet pastry dough around the rolling pin. Unroll the sweet pastry dough into the metal tart tin. Trim the edge by running the rolling pin across the top of the tin, then gently push the pastry a little above the edge of the tin. Use a fork to prick the base all over.
Spread the ricotta and chocolate crostata filling on top of the sweet pastry in the base of the metal tart tin. Re-roll the trimmed sweet pastry into a rectangle approximately 25cm x 15cm in size. Use a knife or fluted pastry wheel to cut long strips. Arrange the strips decoratively over the filling. Brush the sweet pastry with milk.
Bake for 45-50 minutes, or until the sweet pastry is lightly golden. Remove from the oven and allow to cool for 15 minutes. Remove the tart from the tin and allow to cool on a wire rack for a minimum of 2 hours. The Crostata of ricotta and chocolate can be kept at room temperature for 2-3 days – Buon appetito.
600g ricotta|100g caster sugar|Zest of 1 orange|1 vanilla bean, split lenthways and seeds removed (alternatively 1 teaspoon of vanilla bean paste)|100g dark chocolate bits|Milk for brushing pastry