Kaastengels (cheese cookies)

1 stick unsalted butter, melted
1/2 cup cheese (grated Edam or Gouda cheese)
1 cup all-purpose flour
1 egg yolk

2 egg yolks for garnish

Preheat oven at 350 F. Mix all the ingredients and form the cookies. Put it in the oven for 15 minutes, spread the egg yolk for garnish, and bake again for 15 minutes.