Make the custard

1. In a saucepan, beat the egg yoks and 6 Tbsp sugar together with a whisk. Add the milk and whisk to combine. 
2. Heat the mixture to boiling over mediaum heat, whisking constantly. Once boiling, reduce to low heat. Boil and stir for one minute longer. Remove from the stovetop. The mixture should be thick.
3. Pour the custard mixture into a bowl and press a piece of plastic wrap onto the surface. Refrigerate until chilled, about 1 hour.

Make the crust while the custard chills

1. Preheat the oven to 375 degrees.
2. Place the ladyfingers in a food processor and pulse until course crumbs. Or place in a zip top bag and use a rolling pin to crush cookies into crumbs.
3. In a bowl, combine the cookie crumbs, melted butter, sugar and espresso powder. 
4. Press the crumb mixture into a 9-inch tart pan with a removable bottom. I have found it easiest to place the tart pan on a pizza pan. Make sure the mixture is spread evenly across the bottom and up the sides. 
5. Bake the crust for 6-7 minutes, until golden brown.
6. Remove from the oven and let cool.

Finish filling and assemble

1. Once the crust is cooled and the custard is fully chilled, remove the custard from the fridge and using a handheld mixer beat in the marscapone cheese.
2. Pour the filling mixture into the chilled tart crust and carefully spread it to the edges. 
3. In a chilled bowl and with clean beaters, beat the heavy whipping cream and vanilla until stiff peaks form. 
4. Spread the whipped cream topping atop the custard filling. 
5. Sprinkle the top of the tart with cocoa powder.
6. Chill in the fridge an hour or two before enjoying.