I found the recipe in here, the recipe is not clear. I am so curious about this cookies , one of the ingredient is condensed milk. I have to guess and made some adjustment with this recipe, taste good, but I think next time , I will cut the cookies first before I put in the oven, right now you can see some of the crack icing on the top.
1 1/2 cup flour
1 cup butter
5 tbs condensed milk
2 egg yolk
3 tbs milk powder
Mix all ingredients together, spread in the cookie pan, the thickness of the cookies 6 mm.
Put the icing on the top, cut in to rectangle or square, bake for 30-40 minutes at 150 C.