Method (vanilla cookie dough)

1. Add the flour, sugars, butter and vanilla into the bowl of a food processor and pulse a few times adding in the milk and continuing to blend until a smooth ball of dough forms. 
2. Shape the dough into a disc and wrap loosely with cling film or grease proof paper. Place into the fridge while you make the pistachio dough.

Method (pistachio cookie dough)

1. Add the pistachio nuts into a mini food processor / blender and blend until ground / fine.
2. Add the ground pistachios, flour, sugars and butter into the bowl of a food processor and pulse a few times adding in the milk until a smooth ball of dough forms. Optional: you can also add in a small drop of green food gel when adding in the butter for a more vivid ‘green pistachio’ colour.
3. Shape the dough into a disc and wrap loosely with cling film or grease proof paper. Place into the fridge for at least 1 hour or until it feels firm / not sticky.

Method (rolling the cookie)

1. Unwrap the vanilla cookie dough and place it on a sheet of grease proof paper dusted with flour with another sheet on top. Use a rolling pin to roll out the dough into a rectangle shape until it’s approximately 1/8 inch in thickness. It should be be roughly around 8 by 13” in size. Peel away the top piece of baking paper. The amount of cookies including the swirl depend on the thickness and size of your dough. The thinner the dough, the more swirls you’ll achieve. 
2. Roll out the pistachio dough doing the same method in-between two sheets of grease proof paper. Peel away the top piece of baking paper. Try to make it a similar size and thickness. 
3. Gently lift and place the pistachio dough on top of the vanilla dough. Place a piece of baking or baking paper on top and use a rolling pin to roll the two doughs together, just a few rolls will be great hen remove the paper.
4. Starting from the shorter side, very tightly roll the dough together, similar technique as a yule log (watch video for reference). Once it’s in a tight log, wrap it in cling film and chill for at least 2 hours or until firm.

Method (bake)

1. Preheat oven to 180°C fan and line a baking tray with grease proof paper.
2. Once the dough log is firm, use a sharp knife to cut the log into cookies, appropriately 1/4 inch thick.
3. Place the cookies on the lined tray, making sure to have them apart from each other as these cookies will spread in the oven. It’s best to bake a few cookies at a time keeping the rest of the cookies in the fridge ready for baking once the first batch has baked.
4. Place into the middle of the oven and bake for 10 minutes or until lightly golden in colour. Slightly underbaked cookies will be softer then slightly over-baked, as these will be more of a biscuit texture.
5. Remove the cookies from the oven and allow them to cool on the tray for at least 10-15 minutes before transferring them on to a cooling rack to cool fully as they will firm up. If you try to remove them when they’re first out of the oven, they will be very soft and could break. Repeat for the whole batch of cookies.
6. You can enjoy them as they are or serve with a delicious chocolate dip.

Method (chocolate  dip)

1. Melt the chocolate either in the microwave or over the hob using a bain-marie , until melted.  If you wanted to temper the chocolate you can do, I have the best tempering chocolate tutorial in my baking book. 
2. Dip a corner of the cookies into the melted chocolate, allowing any excess to drop back into the dish / pan. Repeat until all the cookies are dipped in chocolate.
3. While the chocolate is wet, sprinkle some ground pistachios so it sticks.
4. Place into the fridge to set the chocolate. 
5. Serve and enjoy!