Triple Chocolate Chunk Cookies

My most favorite cookie!  When we lived in Halifax we discovered these insanely good cookies from the Atlantic SuperStore bakery.  There were to die for!  And a dozen of these babies never lasted long at our house.   (Like, two days at the most!)

I've been on a quest for the past seven years for a recipe to replicate those cookies.  I have scoured the internet for tips to achieve specific cookie textures because, although I mastered the flavor a while back, the texture was not what I wanted.  Finally, after lots of failed attempts, I've come close.  Not exact, but close enough that I, as picky as I am, am totally satisfied.

Ingredients:
*1/2 cup butter, softened (Allow to come to room temperature over several hours.)
*1/2 cup sugar
*1 cup brown sugar
*1 egg
*1 egg yolk
*1 tsp. vanilla
*1/2 cup cocoa
*1 1/2 cups flour

*1 tsp. baking powder
*1/4 tsp. salt
*1 cup assorted chocolate chips (milk chocolate, white chocolate, and dark or semi-sweet chocolate)

Directions:
1.  Combine flour, soda, and salt.  Mix and set aside.

2.  Using a whisk attachment, cream butter on high until fluffy.

3.  Add sugars.  Beat on high until well mixed.

4.  Add eggs and vanilla.  Beat until fully incorporated.

5.  Mix in cocoa powder.

5.  Switch to paddle attachment.  Mix in chocolate chips.

6.  Gently mix in flour mixture just until incorporated.  Do NOT over-mix!

7.  Roll into 1.5 oz balls and place on ungreased cookie sheet.

8.  Flatten slightly with bottom of drinking glass.

9.  Bake at 375-degrees for 9 minutes.  Do NOT over-bake!

Notes:
-Do not use margarine.  Real butter is a must for this recipe.

-Baking time may vary from over to oven.  I think it's better to have soft, gooey cookies than cookies that are too crisp because they baked too long.

-I have no idea how many cookies this recipe yields.  The full amount of dough never makes to the oven.  Lots of it ends up in my belly first.

-I suggest doubling this recipe.