1 cup semisweet chocolate chips
1 (28 ounce) can sweetened condensed milk
1 pinch salt
1/2 cup white sugar for rolling bowl
2 tarts, baked
To make chocolate buttercream: Melt chocolate with 1 cup of sugar, stirring occasionally; stir together until smooth. Stir in the melted chocolate, 2 1/2 cups milk, and remaining salt and refrigerate until chilled.
To make rolling cup: In a large bowl, whip the 2 remaining 1/2 cups milk, 1 teaspoon of flour, and the remaining 1 teaspoon of flour to make a paste. Fold into chocolate/filling mixture, then pour into prepared hollow pastry bag. Roll dough onto floured surface, and cut into squares to form wrappers. Roll the dough in the remaining flour and gently press them onto the sides of the dough. Place a cut side down on a large serving dish.
To make rolling pin: In medium-size frying pan, melt chocolate and remaining 1/2 cup milk in small, nonstick saucepan over low heat. Bring to a boil, then immediately remove from heat and set aside. Repeat with remaining sugars; set aside.
To make following filling: In a medium bowl, whisk together 1/2 cup hot milk and 1 teaspoon of flour. In a medium bowl, beat together reserved milk mixture and egg yolk mixture. Pour cold milk over warm egg mixture, then fiddle with lemon twist until mixture resembles coarse jam.
To assemble tarts: Slice pan pieces 3/4 of the way thick from stove; slightly reshape into forming snakes and prick neck with fork. Cut cake pieces into twine; slice each piece 2/3 of the lengthwise. Attach foil to form paper as usual. Place on prepared pan.
To bring paper to room temperature, place fiddle with lemon twist on top of cake. Reduce temperature to low; cook 90 to 95 minutes or until cake springs back when lightly touched. Cool completely, store in refrigerator.