In a saucepan, melt 1 teaspoon butter over low heat. Tear the filo pastry sheets into small pieces and add to the pan. Toast over medium heat for 5 to 10 minutes until golden and crisp.

Microwave the pistachio cream for 10 to 20 seconds until soft. Stir it into the toasted filo mixture, reserving 2 tablespoons for drizzling later. Let the mixture cool completely.

In a large bowl, beat the softened butter until smooth but not fully creamed. Add both sugars and mix until combined into a sandy texture.

Add the eggs and mix. The batter may look messy at this stage.

In a separate bowl, whisk together the self-raising flour, plain flour, cocoa powder, and salt. Gradually fold the dry ingredients into the wet mixture until combined.

Stir in the milk chocolate chips.

Line a baking tray with parchment paper (make sure it fits in your freezer). Scoop heaped tablespoons of dough and flatten in your palm. Place 1 teaspoon of pistachio filling in the center and seal the dough around it to form a ball.

Repeat to make 12 cookie balls. Freeze for 90 minutes.

Preheat the oven to 200°C fan / 220°C conventional. Place the baking tray in the oven to preheat for 5 minutes.

Place 4 to 5 frozen cookie balls on the hot tray, spaced apart. Bake for 12 to 15 minutes, until edges are set and centers remain soft.

Let cookies cool on the tray for 15 minutes.

Warm the reserved pistachio cream slightly and drizzle or pipe over the cooled cookies. Serve warm or store at room temperature for up to 4 to 5 days.