4 tablespoons butter
4 (1-ounce) squares unsweetened chocolate
2 cups sugar
4 extra-large eggs
2 cups sifted all-purpose flour 
2 teaspoons baking powder
1/4 teaspoon salt
1/2 cup chopped walnuts
1 cup powdered sugar

In a large, heavy saucepan over low heat, melt butter and chocolate. Cook, stirring occasionally, until smooth; remove from heat. With a heavy wooden spoon, stir sugar into warm chocolate mixture. Stir in eggs, one at a time, beating well after each addition. Sift in flour, baking powder, and salt; stir until smooth. Stir in walnuts.

NOTE: This will be a soft dough and must be refrigerated. It may be left in saucepan or transferred to a bowl. Either way, cover and refrigerate, preferably for 1 1/2 hours; dough may be refrigerated longer or overnight, if you wish.

Preheat oven to 300 degrees. Adjust two racks to divide oven into thirds. Line cookie sheets with aluminum foil.

In a small bowl, place powdered sugar. Sugar palms of your hands with some of the powdered sugar. Roll dough into 1 1/2-inch balls. Roll balls around in powdered sugar and place 2 inches apart onto prepared cookie sheets.

Bake 20 to 22 minutes or until tops of cookies are barely semi-firm to touch. Reverse position of sheets top to bottom and front to back once during baking to ensure even baking. Remove from oven and cool on wire racks.

DO NOT OVERBAKE - these should be slightly soft in the centers. (If you bake only one sheets at a time, bake high in oven.)