Preheat oven to 350 degrees F and grease an 8x8" baking dish.
Mix all ingredients in a large mixing bowl, stirring well to ensure no dry lumps of flour remain.
Pour into your prepared baking dish and bake for 45 minutes or until a toothpick inserted in the center comes out clean.
Allow butter mochi to cool before slicing and serving. This butter mochi is best eaten fresh, as it dries out more quickly than some of my other recipes. However, leftover butter mochi can be kept in an airtight container in the fridge or frozen; just let it come back to room temperature before eating.
