Brownie Cookies with Buttercream Frosting

I developed this recipe to have chocolate cookies that were also festive.  I love to make sugar cookies, but I also love chocolate.  It just seemed unfair that the only options for using all the fun festive sprinkles that I have are cupcakes or sugar cookies.  I also love the flavor of brownies with buttercream, but at times they just aren't as portable as they should be.  These particular cookies were made to go to a tailgater for a football game, which is a place where portability is a necessity.  They were a pretty big hit.

Makes about 60 cookies

1 3/4 cups semisweet chocolate chips
6 oz unsweetened chocolate
3/4 cup butter
2 cups sugar
1 1/2 teaspoon vanilla
6 eggs
1/4 teaspoon salt
2 cups flour
Basic Buttercream

1. In heatproof bowl, combine chocolates and butter.  Heat mixture in the microwave for about 2 minutes--stirring every 30 seconds--or until all chocolate and butter is melted.  Set mixture aside and allow to cool for 5 minutes.
2. Mix sugar into melted mixture.  Stir in vanilla.  Mixture will appear grainy at this point.  Stir in eggs, a few at a time, and beat well.  Make sure eggs are incorporated before adding dry ingredients. Measure salt into mixture and stir.  Add flour, one cup at a time, and beat well.  Be sure to scrap the bottom of the bowl well, as flour seems to collect there very well with this recipe.
3. Cover cookie sheet with parchment paper.
4. Drop scoops of dough onto prepared cookie sheet.  You will want each cookie to be about 2 tablespoons of dough.  Bake cookies in a 375 degree oven for about 10 minutes.  As these are very dark cookies, you will be able to tell that they are done when they are evenly puffed, the tops are dry, and the edges are crackled.  Allow cookies to cool on the cookie sheet for 1-2 minutes before moving them to a cooling rack to cool completely.
5. Once cookies are completely cool, frost them with about 1 tablespoon of buttercream.  Add sprinkles, if desired.