Prep 20 mins
Cook 40 mins
These squares are very rich.
- 5 ounces bittersweet chocolate or 5 ounces semisweet chocolate, chopped into pieces no bigger than 1/4 "
- 2 eggs, separated at room temperature
- 1 teaspoon vanilla extract
- 1 egg white, at room temperature
- 1⁄8 teaspoon cream of tartar
- 1⁄2 cup cocoa
- 2 tablespoons all-purpose flour
- 2⁄3 cup sugar
- 1⁄4 cup sugar
- 3⁄4 cup skim milk
- 9 X 9 inch cake pan.
- Baking pan or roasting at least 2 inches deep and large enough to hold the cake pan with at least 2 inches to spare on each side.
- Position the rack in the lower third of the oven and preheat to 350 degrees.
- Line the bottom and sides of the pan with foil.
- Put a kettle of water on to boil for the bain marie when baking in the oven.
- Place chocolate in a large mixing bowl.
- Combine the 2 egg yolks with vanilla in a small bowl.
- Place the 3 egg whites in a medium bowl with cream of tartar.
- Set all 3 bowls aside.
- Combine the cocoa, flour and 2/3 cup sugar in a 1 1 1/2 quart heavy bottomed saucepan.
- Whisk in enough of the milk to form a smooth paste.
- Mix in the remaining milk.
- Cook over medium heat, stirring constantly with a wooden spoon, to prevent burning (especially around the bottom edges of the pot), until mixture begins to simmer.
- Simmer very gently, stirring constantly, for about 1 1/2 minutes, or until the mixture visibly thickens.
- Pour the hot mixture immediately over the chopped chocolate.
- Stir until chocolate is completely melted and smooth.
- Whisk in egg yolk mixture.
- Set aside.
- Beat the egg whites and cream of tartar at medium speed until soft peaks form.
- Gradually sprinkle in the remaining 1/4 cup of sugar, beating at high speed until stiff but not dry.
- Fold a quarter of the egg whites into the chocolate mixture to lighten it.
- Fold in remaining egg whites.
- Scrape mixture into the cake pan and spread evenly.
- Set cake pan in baking pan and place on oven rack.
- Pour enough boiling water into the baking pan to come a third to halfway up the sides of the cake pan.
- Bake for exactly 20 minutes.
- The cake will only be about 3/4 inches tall.
- The surface will spring back when gently pressed but cake will still be quite gooey inside.
- Remove cake pan and water pan from oven.
- Remove the cake pan from the water and cool completely on a rack.
- Cover with plastic wrap and refrigerate overnight before serving.
- Refrigerate up to 2 days or freeze up to 2 months.
- After the truffle sheet is well chilled, lift the edges of the foil to remove the truffle sheet from the pan.
- Cut the sheet into 7 strips, each about 1 1/4 inches wide, using a long thin sharp knife dipping in hot water and wiped dry between each cut (the cake is very sticky) or cut with dental floss.
- Cut each strip into 7 squares.
- Transfer each square to a fluted paper candy cup and or arrange on a serving platter.
- If garnishing with raspberries, simmer the preserves for a minute or until thick and sticky.
- Touch the hot preserves with the bottom of each berry before placing it on the truffle square.
- Refrigerate until serving.