Brown your butter: In a saucepan, melt butter over medium heat until it begins to foam.
When butter is foaming, add dry milk powder, if using.
Stir your butter and continue cooking over medium heat until melted butter just begins to turn a light amber brown. Turn off the stove. Butter will continue to darken in color due to residual heat. Set aside while you prepare the rest of your ingredients.
Preheat oven to 350 degrees and grease and line a 9x13" metal baking pan.
In a large bowl, whisk mochiko, cornmeal, sugar, salt, and baking powder.
Add eggs and evaporated milk, whisking to combine.
Lastly, add in the browned butter, which should have cooled slightly by this time.
Mix batter well and pour into prepared baking tin.
Bake for 35-40 minutes or until a toothpick inserted in the center comes out clean.
You can store leftovers in an airtight container at room temperature for up to a week.