Deep chocolate cookies

Here is the recipe instructions. All 3 chocolates are mentioned as to when they are used.

" In the microwave, nuke the semi-sweet chocolate chips until just barely melted, stirring to melt the last few chips. Set aside to come to room temperature.

Cream the butter with the sugar and molasses until lightened and fluffy. Add the egg and vanilla extract and cream again. Fold in the room temperature melted chocolate until combined.

In a separate bowl, whisk together the flour, salt, baking soda, and cocoa powder. Stir into the butter mixture just until all the flour is incorporated (the dough will be pretty tough). Stir in the milk chocolate chips.

Roll the dough into tablespoon-sized balls. Bake on a parchment-lined baking sheet for 8 minutes, then leave on the parchment to cool at least 10 minutes before eating. "

The melted semi-sweet chips get mixed in after adding the egg and vanilla extract. The cocoa powder is whisked together with the dry ingredients, and the milk chocolate chips get stirred in at the end.

I still don't understand the ingredients lists 3 different chocolates semi sweet, milk chocolate, and cocoa powder when are they all used
Thanks

The recipe also appears on her blog here: http://www.biggirlssmallkitchen.com/2009/11/big-girls-small-kitchen-book.html and it instructs to fold in the room temperature melted chocolate after adding in the egg and vanilla extract.