Serves 16 squares.
1 cup semi-sweet chocolate chips
1 stick (½ cup) butter
3 eggs
1 cup sugar
¾ cup flour
1 pinch salt
3 tbsp. cocoa powder
1 tsp. baking powder
½ cup chopped walnuts (optional)
Preheat oven 375°.
Grease and flour a 9-inche square oven-safe pan.
Beat the eggs with the sugar until mixture gets a lighter color.
In a microwave-safe bowl, microwave in low power the butter and the chocolate chips 30 seconds, stir, and another 30 seconds, repeating until melted and blend. Once it is melted do not heat longer as it will burn. Add to the eggs and sugar.
Sift in the flour, baking powder, cocoa powder and salt. Mix without overbeating, and last incorporate the walnuts.
Spread in the pan and bake for approximately 35 minutes. When you insert a toothpick, it does not to come out entirely clean.