My Wife's Friend's Brownie Recipe Passed Along from Her Mother

Someone somewhere knows where this recipe started.  My wife's mother raved about this recipe from one of my wife's friends from way back.  We just call them Angela's Brownies.  Thanks Angela.  And please extend our gratitude to whoever gave the recipe to you. 

Ingredients
1 1/4 c. all purpose flour
3/4 c. cocoa
3/4 tsp. baking powder
1/2 tsp. salt
3 eggs
1 1/2 tsp. vanilla extract
2 c. sugar
2 sticks unsalted butter, melted

The Method
Preheat oven to 325 degrees.  Add flour, cocoa, baking powder and salt to large bowl and mix together.  In a separate mixing bowl add eggs and vanilla extract and beat on medium speed while slowly adding sugar until creamy.  Continue to mix while slowly adding butter.  Decrease mixer speed and add remaining dry ingredients.  Return mixer to medium speed and beat until ingredients are evenly combined.  Batter will be thick.  Spray 9 x 13 baking pan dish with canola oil and spread batter evenly.  Bake for 30 minutes.

Food for Thought
Butter is good.  On paper, this is not vastly different from many other brownie recipes but on your tongue, these brownies are special, with hints of buttery, caramel-like richness that makes your brain superimpose flavors from ingredients that are not there.  But speaking of adding ingredients, my mother-in-law's twist is to add chocolate chips.  My wife skips the chocolate chips (or should I say she saves them for different applications) and adds 1/2 cup chopped pecans.  Try this and let the decadent realities and the related gustatory hallucinations begin.