Place 1 cup semi-sweet chocolate finely chopped (or chips) in microwave safe measuring cup and add in 2 tablespoons butter. Heat for 45 seconds, then remove and stir. If chocolate is not all melted, return to microwave for 10 second increments until fully melted.
Sift flours, baking soda, baking powder and salt into a bowl and set aside.
Using a mixer with a paddle attachment, cream room temperature butter and sugars until light and fluffy – about 5 minutes. Add eggs one at a time.
Slowly add in melted (and slightly cooled) chocolate and vanilla.
With mixer on low speed, add dry ingredients slowly, mixing until just combined. Fold in chocolate chips.
Refrigerate dough for 24-36 hours. (Do not skip this step!)
When ready to bake, preheat oven to 350. (325 convection)
Drop spoonfuls of dough onto baking sheet. Bake for 10-12 minutes. Do not over bake. Slightly gooey centers is the best way to eat!