This is a traditional Hawaiian butter mochi recipe. It is typically described as a cross between a butter cake and a Japanese mochi, with a delicate, buttery flavor and a chewy texture.
Place the butter in a microwave-safe bowl. Melt butter in the microwave in 20 second increments, then set aside to cool for a little bit.
In a medium bowl, beat the milk, sugar, rice flour, coconut milk, eggs, melted butter, baking powder, coconut flakes/shredded coconut, and vanilla extract together with a whisk until thoroughly combined.
Pour the butter mochi batter into the prepared pan.
Bake 60 minutes until the top is brown and cake tester inserted into the center comes out clean.
Remove to a wire rack, then let cool completely.
Once completely cooled, cut into 16 roughly 2-inch pieces with a sharp knife.
Notes
Store in an airtight container at room temperature for up to 2 days. You can also wrap individual servings tightly in plastic wrap and freeze for up to a month. If you just can't wait, eat straight out of the baking pan with a spoon. If you're more civilized, serve topped with ice cream or whipped cream.