If your nuts haven't been toasted, roast them for 8-10 minutes on a baking tray in a preheated oven at 175°C-360°F. Shake them well at the halfway point before removing from the oven and allowing them to cool completely.
In a small bowl, mix 1 T chili flakes with 1/3 c gula djawa syrup.
In another bowl, mix 2 c plain flour with 1/4 t baking powder, 1/2 t lemongrass, 1 t galangal and 2 T coconut powder.
Use a hand or stand mixer to beat 3/4 c butter with 7/8 c sugar and 1 t salt until fluffy. Make sure that you push any of the batter that has splashed upwards to the edges of the bowl back into the batter every now and again.
Add 3 egg yolks and 1 t vanilla extract and beat for another minute. Then add the gula djawa-chili mixture and beat for another minute until smooth and creamy.
Set your mixer to the lowest setting and slowly mix the flour-spice mixture into the dough.
Finally, use a wooden spoon to fold in 1/2 c dried coconut cubes, coarsely chopped 3.8 oz-110 gr milk chocolate and nuts into the dough.
Divide the dough into two portions. Roll each portion into a roll of about ± 10"-25 cm long and ⌀ 1.2"-3 cm thick. Wrap the rolls tightly with plastic wrap, then roll them as smooth and round as possible.
Let the rolls freeze for at least 35 minutes, until the outside is firm. Not too long! Otherwise, you won't be able to get through.
Preheat the oven to 175°C-360°F. Using a sharp knife, cut the first roll into 0.2"-1/2 cm thick slices and spread them on a baking tray lined with parchment. Keeping about 1"-2.5 cm distance between each cookie.Note when cutting the logs you won't necessarily get neat perfectly flat cookies, but the texture is part of the fun here. So don't worry about it too much. If cookies look like they might come apart just push them together a little bit on the sheet, it'll all work out in the oven. Bake the cookies ± 10 minutes, giving the sheet a half-turn at the 5 minute mark to ensure the cookies bake evenly.
Allow the cookies to cool completely on the baking sheet and then bake the second batch if necessary, or store it in the freezer for a second portion of cookies for up to 1 month.