Directions

To make the cookies

1. Preheat your oven to 175°C. Line a large baking tray with parchment paper.
   

2. In a bowl, whisk together the flour, cocoa powder, baking soda, and a pinch of salt.
   

3. In another bowl, beat the butter, sugar, and brown sugar until light and fluffy. Add the eggs one at a time, mixing it in well before moving on. Add the vanilla and fold it in.
   

4. Add the flour mixture gradually by the tablespoon, mixing before adding the next. Take care not to overmix, and then gently fold in the chocolate chips.
   

5. Add the dough by the tablespoon onto your baking tray, spacing them out. Bake for no more than 8-10 minutes. The cookies, when you take them out of the oven, should be almost set with a soft center. Gently transfer the cookies to a wire rack and let them cool completely.
   

To make the filling

1. In a heavy-bottomed saucepan, add the milk powder, sugar, butter, and egg yolks. Turn the heat on low and start cooking, stirring constantly, till the butter melts and the sugar has dissolved completely. Turn the heat up to medium, and continue cooking, stirring constantly, till the mixture is thick and bubble, with a pudding-like consistency and takes on the colour of a light caramel.
   

2. Turn the heat off and remove the saucepan from the heat and stir in the walnuts, coconut, and vanilla. Let it cool for 5-10 minutes, stirring every 2-3 minutes, till the mixture reaches a spreadable consistency.
   

3. Assemble the cookie sandwiches by spreading the filling on one cookie, and then topping with another.