Road Kill Cookies

1 C butter, softened
2/3 C sugar
2 large egg yolks
1/2 tsp vanilla extract
2 1/4 C all purpose flour
1/4 C poppy seeds
1/2 kosher salt

Cream butter; add sugar gradually, mixing until light and fluffy. Add egg yolks one at a time mixing well after each addition. Stir in vanilla. Combine flour, poppy seeds and salt ; add to butter mixture, mixing until ball of dough forms. Chill dough 1-2 hours. Form dough into 1" balls; place on a lined cookie sheet 2" apart. Press thumb in center of each cookie leaving an indentation that will be filled with frosting after baking. Bake at 300 degrees for 20-25 minutes. Remove from oven when the edges have the slightest hint of brown.

Chocolate Frosting:
1 C sugar
1/4 C cocoa
1/4 C buttermilk
1/4 C butter
1/2 tsp vanilla extract

Combine sugar, cocoa and buttermilk in a heavy saucepan. Bring to a boil for two minutes, stirring constantly. Remove from heat; stir in butter and vanilla. Whisk until mixture thickens slightly. Fill cookies with frosting, let stand until frosting hardens.