Melt the chocolate over low heat, stirring often. Blend tofu in a food processor. Add the vanilla and melted chocolate and blend again, stopping once or twice to scrape down the sides of a bowl with a rubber spatula.
Beat the egg whites to soft peaks. Place the tofu chocolate mixture into a bowl and slowly fold in the egg whites with a rubber spatula. Scoop the filling into the pie crust and refrigerate for several hours before serving.
Serve with a bit of whipped cream or raspberry sauce (or simply thin raspberry jam with a bit of water and lemon juice). Don't say tofu, say terrific.
*RAW EGG WARNING
Food Network Kitchens suggest caution in consuming raw and lightly-cooked eggs due to the slight risk of Salmonella or other food-borne illness. To reduce this risk, we recommend you use only fresh, properly-refrigerated, clean, grade A or AA eggs with intact shells, and avoid contact between the yolks or whites and the shell.