Preheat oven to 350*. Butter and dust with flour around a 9×13
glass or stainless steel baking pan. (Or halve this recipe for an 8×8.) In a heavy
large saucepan, melt chocolate and butter over low heat, stirring as it gets smooth. Remove from heat and cool. Stir in sugar, vanilla and eggs and mix well. Add in flour, salt and baking powder and mix well. Stir in
chocolate chips. Pour batter evenly into the pan and bake for 25-40 minutes (depends on how much oven temps might vary), until the middle is set but not too firm or they’ll be dry. (Less time for an 8×8.)