Line two large baking trays with baking paper.

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

In a large mixing bowl, beat the dairy-free butter, white sugar, and brown sugar until light and creamy using an electric mixer.

Add the egg and vanilla extract to the butter mixture, and beat until well combined.

Gradually add the dry ingredients to the wet ingredients, mixing until a soft dough forms.

Roll the dough into small balls, about 1 tablespoon each, and place them on the prepared trays, spacing them about 5 cm (2 inches) apart. Place the trays in the fridge for 30 minutes to an hour before baking to ensure they hold their shape when baking.

Preheat the oven to 180°C (350°F). Get the trays out of the fridge and use your thumb or the back of a teaspoon to gently press a small indentation into the centre of each cookie.

Bake for 10 minutes or until the cookies are set but still soft. Remove from the oven and allow the cookies to cool on the trays for 5 minutes, then transfer them to a wire rack to cool completely. When the cookies are removed from the oven, the centres may have puffed up - just use your teaspoon to press the indents back in.

Once the cookies are cool, make the peppermint ganache filling. Mix the peppermint extract with the coconut milk in a small heat-proof bowl and place in the microwave until hot but not boiling. Pour the milk over the chopped chocolate and let sit for 5 minutes. Use a metal spoon to mix the chocolate ganache together until thick and shiny.

Spoon the ganache into the centres of the chocolate cookies and top with a sprinkle of crushed candy canes. Allow the ganache to set before stacking and storing in a cool dry place or in the fridge.