Whisk together the dry ingredients, making sure that the cocoa isn't lumpy and is well mixed in.
In your mixing bowl, cream together the butter and sugars until it's wonderfully light-colored and fluffy.
Then add in your eggs, one at time, beating them in completely and toss in the vanilla as well.
When the vanilla has been mixed in, slowly add in the dry mixture little by little, until it has all been added and mixed in.
Drop by large rounded tablespoonful onto ungreased or parchment lined cookie sheets. Flatten the cookies slightly to make sure we get wide enough cookies for ice cream sandwiches!
Bake in the 350 degree oven that you have preheated, of course, for 9-10 minutes. Remember that the key to wonderful cookies is just underbaking them by a minute or so and this is especially important with these cookies as the cocoa can dry things out.
Leave them for a minute or two on the cookie sheet, then transfer to a baking rack and cool completely. These are a soft, chewy cocoa cookie that are perfect for this purpose.
Take one, spread the ice cream of your choice on the bottom then find a mate and sandwich them together.