Be sure to soften your butter to room temperature. Combine the butter and egg yolk by mixing or whipping. Be sure not to overmix.
If needed, prepare your cheese. The Edam cheese came in a small wheel. Grating it before mixing is probably necessary.
Add all purpose flour, cornstarch, salt, and Edam cheese. Mix until it comes together into a dough. It may seem like it won't form a dough at first but keep going!
Shape the dough into a flat disc, wrap in plastic wrap, and put it in the refrigerator for 30 minutes.
Begin shaping your dough. Roll the dough into a rectangle that is ¼ inch thick. Then cut the dough into small rectangles. I cut mine ¾ inch wide and 3 inches long. Place these pieces on a parchment lined baking pan. You may need two baking pans.
Make an egg wash by beating a whole egg. Brush this on top each piece and then and top with gouda cheese or whichever salty cheese you have chosen.
Put the cookies in the freezer for 15 minutes. Preheat the oven to 300℉ (150℃)
Once the cookies are done with their time in the freezer, take the baking pan out and immediately put it in the preheated oven. Bake for 35 minutes or until fully cooked.
Let it cool before enjoying!