In a medium bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt. Set aside.

In a large bowl, using a hand mixer or stand mixer, cream together the softened butter and sugar until light and fluffy, about 2-3 minutes. Beat in the egg and vanilla extract, mixing until combined.

With the mixer on low, add the red food coloring and buttermilk to the wet ingredients, and mix until you achieve a vibrant red color. Gradually add the dry ingredients, mixing just until the dough comes together. The dough will be soft but slightly sticky.

Cover the dough with plastic wrap and refrigerate for at least 30 minutes.

Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper.

Roll the chilled dough into 1-inch balls and place them 2 inches apart on the prepared baking sheets. Lightly flatten each ball with the palm of your hand.

Bake for 10-12 minutes, or until the cookies have set around the edges but are still soft in the center.

As soon as the cookies come out of the oven, gently press a peppermint kiss into the center of each one. Immediately sprinkle crushed peppermint candies around the base of the kiss while the cookies are still warm.

Allow the cookies to cool on the baking sheet for 5 minutes, then transfer them to a wire rack to cool completely.