Preheat your oven to 350°F (175°C).
Grease and flour a 9x5-inch loaf pan.
In a medium bowl, whisk together flour, cocoa powder, baking soda, and salt.
In a large bowl, cream together butter and sugar until light and fluffy.
Add eggs one at a time, mixing well after each addition, then mix in vanilla extract.
Alternate adding the dry ingredients and buttermilk into the wet mixture, mixing until just combined.
Fold in crushed peppermint candies and chocolate chips gently.
Pour the batter into the prepared loaf pan, smoothing the top.
Bake for 55–60 minutes, or until a toothpick inserted in the center comes out clean.
Allow the loaf to cool in the pan for 10 minutes before removing it to a wire rack.