Preheat the oven to 350 degrees and coat a 9-inch bundt pan with non-stick baking spray.

In a large bowl, mix together the cake mix, milk, eggs, butter, and peppermint extract until smooth and smooth.

Pour the batter into the bundt cake pan and bake for 35-45 minutes, or until a toothpick inserted near the center comes out clean.

Allow the cake to cool in the cake pan for 15-20 minutes. Then, carefully transfer the cake to a plate or cake stand and allow it to cool fully.

In a small pot, bring the heavy whipping cream and espresso powder to a slow simmer, stirring often.

Using a strainer, strain the heavy whipping cream into a heat-safe bowl (to ensure there are no clumps of espresso powder remaining).

Add the chocolate chips. Allow to sit for 1 minute, then whisk until smooth.

Pour the ganache evenly over the top of the cooled cake, allowing it to drip down the sides.

Sprinkle with crushed peppermints.