CHOCOLATE CHIP CUSTARD TART

Steps:

• To make the crust dough, cream the butter in the bowl of an electric mixer fitted with the paddle attachment at medium speed for a minute or two. Stop the mixer and switch to the whisk attachment. Slowly add the sugars and mix at medium speed until light and fluffy, then add the eggs, one at a time, mixing until incorporated after each addition. Add the flour slowly, then the vanilla, salt, chocolate chips, and nuts, mixing until blended. Cover and chill for at least 20 minutes.
• Lightly flour a cool rolling surface such as a marble tabletop. No marble tabletop? Just flip over a baking sheet, and flour it generously or lightly flour a big piece of parchment paper or silicone baking mat. Place the dough on the floured surface, lightly flour the top, and roll it with a rolling pin until just under 1/2 inch thick. No rolling pin? Flatten the dough as thinly as you can with your hands. Maneuver the flattened dough into a 9 or 10-inch tart or pie pan. One way to do this is to lift under the dough with a big spatula and slip the pan under the dough. Don't worry if the dough breaks-you can pinch it back together. Once the dough is in the pan, smooth it out and flatten it with your hands and press it against the edges of the tart pan. Use scissors to trim any excess pieces that hang over the sides (you can save these scraps and bake them as cookies later). Cover the dough with plastic wrap or aluminum foil and return it to the refrigerator.
• Preheat oven to 300°F. To make the filling, melt the dark and milk chocolates and butter together in a stainless steel bowl over a saucepan of simmering water.
• In a medium bowl, whisk together the eggs, brown sugar, salt, and vanilla extract and set aside. In a small saucepan, heat the milk and cream to a scald. Slowly add the milk mixture into the egg mixture while stirring briskly. Once the mixture is smooth, stir in the chocolate mixture and let cool to close to room temperature. This is your custard.
• Remove the tart pan from the refrigerator, unwrap it, and put it on a baking sheet. Carefully pour the custard into the tart shell. Place the full tart pan into the hot oven. Take a standard cake pan and fill it halfway up with room temperature water. Place that pan next to the sheet pan in the oven to provide extra moisture for the tart while it bakes. Bake about 40 minutes. You'll see the cookie shell firm up and turn golden brown, and if you shake the pan a little you'll notice the custard moves as a solid, not a liquid. If it still wiggles like a liquid, give it another 5 minutes and try again. When the cookie is golden brown and the center is solid, remove the pan from the oven. Allow to cool to room temperature, then chill in the refrigerator for at least an hour. Serve cold or at room temperature. Slice with a big knife or pie cutter, and top each slice with a small scoop of whipped cream.