Preheat oven to 300F/150°C and line two baking pans with parchment paper.
Mix wet ingredients – In a large bowl, mix butter and egg yolks with a spatula or mixer until just combined. Don't overmix.
Add dry ingredients – Sift in cake flour, cornstarch, and baking powder. Add grated edam cheese and mix until just combined.
Roll dough – Place the dough onto a working surface lined with a silicone mat or parchment paper. Place a plastic or parchment paper on top of the dough and roll the dough into a rectangle with 0.4-inch/1 cm thickness.
Sprinkle with cheese – Use a knife, pizza cutter, or cake scraper to cut the dough horizontally about 1.6-inch/4 cm in width. Brush the top with egg yolk and sprinkle with grated cheddar cheese. Press the cheese to the dough with a spatula.
Cut – Use a knife, pizza cutter, or cake scraper to cut the dough into 0.5-inch/1.2 in cm width and 1.6-inch/4 cm long. Place the cut dough on baking sheets, spaced at least 1-inch/2.5 cm apart.
Bake at 300F/150ºC for 20-25 minutes or until golden brown.
Cool completely on a cooling rack before storing.
Notes
Measuring by weight is recommended for this recipe.