1. Preheat the oven to 375 degrees F. Open up the 2 pieces of pie crust dough and lay one down on your work surface. Dip your finger in water and run it around the perimeter of the dough. Place the second piece on top; the water will help them adhere to each other. Roll out the combined dough to a 12-inch circle and press into a 9-inch tart pan. Use a fork to gently prick holes all over the bottom of the crust. With your rolling pin, roll over the top of the tart pan to trim the excess dough. Place a piece of nonstick foil down onto the dough and fill it with dried beans, uncooked rice or pastry beans. Bake until the tart begins to cook and brown slightly, about 20 minutes; remove the foil and bake until a deep golden brown, for an additional 20 minutes. Set aside to cool while making the filling. The crust can also be made 1 day in advance, cooled and then covered in foil for later use.
2. Heat the cream, milk and sugar in a medium saucepan over low heat until the sugar is dissolved and the liquid is simmering, about 5 minutes. Add the chocolate, turn off the heat and let stand for 5 minutes. Whisk until the chocolate is thoroughly melted and the mixture is blended. Set aside to cool for 5 minutes. Use a rubber spatula to gently fold the egg into the cooled chocolate mixture.
3. Spread the jam over the bottom of the tart. Pour the chocolate mixture into the prepared tart over the jam and bake until the filling is slightly firm but still has a bit of movement in the center, 25 to 30 minutes. Remove from the oven and place on a rack to cool.
4. Dust with cocoa powder and garnish with raspberries. Serve at room temperature or chilled.