The End-All Chocolate Cookies Recipe

1 cup butter
1/4 cup shortening
1 1/2 cups granulated sugar
2 eggs
1 teaspoon vanilla
1 teaspoon salt
3/4 teaspoon baking powder
2/3 cup cocoa
3 or 3 1/2 cups flour

Cream butter, shortening and sugar together. Add eggs and vanilla. Mix well. Add baking powder and salt and mix again. Stir in the cocoa until well blended. Add flour 1 cup at a time. IF YOU ARE GOING TO MAKE COOKIES RIGHT AWAY, ADD 3 1/2 cups flour. If you are going to "chill" the dough, or just wait for another day to make your cookies, STOP AT 3 cups. It will be totally soft and look all wrong, and you will want to ignore me completely and add more flour, but I'm telling you -- DON'T DO IT. Practice self-restraint. You will be glad you did, and I will be proud of you. Roll out on lightly floured surface. Bake at 375 F for 6 1/2 minutes.

There are some things I think you should know:

*** I don't have conversions for the metric world. I'm sorry. Please don't leave me hating messages. But I will tell you that this may be the most forgiving cookie recipe in the world. You can just google conversions and anything that's remotely close to being right will work for these cookies.
*** You don't have to add shortening if that grosses you out or you hate it on sheer principle or you can't find it where you live. It just makes the cookies a little softer. You can omit it entirely or substitute it with butter.
*** If you find that the dough has cracks in it when you try to roll it - don't freak out. It's okay. Just knead it for a minute and it will be ever so smooth and wonderful.