Everybody's Favorite Congo Bars
2/3 cup unsalted butter, melted and cooled
1 pound light brown sugar
3 eggs
2 3/4 cups flour
2 1/2 teaspoons baking powder
1/2 teaspoon salt
1 cup chocolate chips
1 cup chopped walnuts
Adjust rack in lower third of oven and preheat oven to 325 degrees. Grease well a 10 x 15 x 1-inch pan.
In a large bowl, mix together the melted butter, brown sugar and eggs just until blended. Sift the flour, baking powder and salt into another bowl and add this to the egg mixture. Stir in the chocolate chips and walnuts. Spread in the pan (the dough is sticky, so you may want to pat it out with your fingertips).
Bake for 30 to 35 minutes. It will still look soft. Remove from the oven to a wire rack. Cut while warm into 25 squares.