Truffle Bars

1 1/4 cups unsalted butter
3/4 cup cocoa
1 cup plus 1 tablespoon sugar, divided
3 tablespoons all-purpose flour
2 teaspoons vanilla extract
4 eggs, separated
Pureed berries (optional sauce)

Heat oven to 425 degrees F. Grease bottom of 9-inch square pan or pie plate.

Melt butter over low heat.

Beat egg whites with 1 tablespoon sugar until they form soft peaks.

Stir cocoa and 1 cup sugar into melted butter. Remove from heat. Cool about 5 minutes.

Stir in flour and vanilla extract. Add yolks, 1 at a time; beating well after each addition.

Gradually fold egg white mixture into chocolate mixture. Spoon batter into pan.

Bake 18-20 minutes or until edges are firm. Cool and refrigerate for about 4 hours.

Let stand 15 minutes before slicing into 1 1/2-inch squares.

Serve with sauce on the side, if desired.