In a large mixing bowl, beat together 250g of unsalted butter and 150g of sugar until light and fluffy, about 3-5 minutes.
Add 1 egg and 1 tsp of vanilla essence, mixing until well combined.
In a separate bowl, whisk together 250g of flour and 60g of almond flour. Gradually add this dry mixture to the wet ingredients until a dough forms. If too dry, add 1 tbsp of cold water.
Shape the dough into a disc, wrap in plastic wrap, and refrigerate for at least 1 hour.
Preheat your oven to 180°C (350°F). Roll out the dough to about 1/4-inch thickness and cut out shapes with cookie cutters.
Place the cookies on a baking sheet lined with parchment paper and bake for 10-12 minutes until the edges are lightly golden.
Prepare the chocolate filling by heating 150ml of heavy whipping cream until simmering, then stir in 150g of milk chocolate chips until smooth.
Once cooled, spread the chocolate ganache on the cookies with holes and top with solid cookies. Dust with powdered sugar before serving.