1 1/4 cups black and orange mini candy-coated chocolates
Preheat oven to 350 degrees, with racks in upper and lower thirds. Line two baking sheets with parchment paper. Sift flour, cocoa, baking soda, and salt together into a large bowl.
Put butter and sugar in the bowl of an electric mixer fitted with the paddle attachment; beat on medium speed until pale and fluffy, about 2 minutes. Beat in eggs, one at a time. Beat in vanilla. Reduce speed to low; beat in flour mixture. Stir in 1 cup candies.
Drop dough by the tablespoon onto baking sheets about 2 inches apart. Press remaining 1/4 cup candies into tops of cookies.
Bake cookies, switching positions of sheets about halfway through, until just firm, 8 to 10 minutes. Let cool on sheets on wire racks 5 minutes. Transfer cookies to racks, and let cool completely.