First to prepare the tart crust, soften the butter at room temperature or in the microwave (be careful not to melt it);
In a big mixing bowl put the egg yolks, the sugar, and the coarsely diced butter. Work fast to mix it with your hands until you have a grainy texture;
Add the flour and combine the ingredients until you have an even mixture.
Use a spoon or your hands, but try not to warm the dough too much;
Wrap it in plastic wrap and refrigerate for 2 hours;
In the meantime, prepare the ricotta filling. Drain the ricotta to eliminate all the whey;
Then combine the ricotta, sugar, and the egg;
Add the orange blossom and vanilla extract until it’s even and smooth;
Add the chocolate chips and combine well;
Refrigerate for about 2 hours;
When the time is up, take the dough out of the fridge and knead it;
Take a 8-inch (20cm) round baking pan with 1.5 inch (4cm) high sides;
Roll out the cold dough between two sheets of parchment paper;
Roll out a disk big enough to overlap the tart pan;
Place it in the tart pan covering the bottom and the sides;
Trim off the overlapping edges and make a ball of the leftover dough to use for the garnish;
Prick the dough with the tines of a fork;
Evenly spread out the filling;
Roll the extra dough, cut it into 0.5 inches about wide stripes to decorate; seal the edges with the fingers;
Refrigerate the tart for 20 minutes;
Pre-heat the static oven to 350°F (180°C) and bake for about 45 minutes;
Turn off the oven and let the tart rest inside for about 10 minutes;
Open the oven door and let the tart cool down;
When completely cool, generously sprinkle with powdered sugar.