Meanwhile, beat eggs at high speed. Add flour and baking soda and beat until blended. Add chocolate mixture and blend well. Chill dough for 1 hour.
Line baking sheets with parchment. Roll dough into 1" diameter balls. Bake at 350° for 10-12 minutes.
Place unwrapped mint on top of each warm cookies as soon as you remove them from the oven. After the mints have softened, spread the mint over the cookies with a spoon. Let the chocolate set at room temperature.