Preheat the oven to 350°F (175°C). Grease a 9x5-inch loaf pan and set aside.
In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, and salt until well combined.
In another bowl, mix the buttermilk, vegetable oil, eggs, vanilla extract, and peppermint extract until smooth.
Pour the wet ingredients into the dry ingredients and stir until just combined. Be careful not to overmix.
Fold in the chocolate chips and crushed peppermint candies gently.
Pour the batter into the prepared loaf pan and smooth the top with a spatula.
Bake for 55-65 minutes, or until a toothpick inserted into the center comes out clean.
Let the bread cool in the pan for about 10 minutes, then transfer it to a wire rack to cool completely.