Measure and combine strong bread flour and extra strong bread flour in a mixing bowl based on Baker's percentage.

Add salt, sugar, and skim milk powder to the flour mixture.

Dissolve instant dry yeast in water and add to the dry ingredients.

Begin kneading the mixture to form a dough, then incorporate unsalted fermented butter.

Knead the dough until it reaches a smooth and elastic consistency.

Place the dough in a lightly oiled bowl, cover, and let it rise in a warm place until doubled in size.

Punch down the dough to release air bubbles, then divide and shape it to fit the corn toast bread mold.

Cover the shaped dough in the mold and let it rise again until it reaches just above the rim of the mold.

Preheat the oven to the required temperature and bake the bread until it develops a hard crust and golden brown color.

Remove the bread from the oven and let it cool on a wire rack before slicing.