✔ Updated · fixed the butter amount, bake time and doneness cues, plus storage and swaps
Hawaiian butter mochi is a chewy, custardy cake made from sweet rice flour and coconut milk, with crisp, caramelized golden edges. It's a one-bowl bake, and it's naturally gluten-free.
At a glance
The one tip that matters: Wait until it's fully cool before cutting. Warm butter mochi is gooey and sticks to the knife; cool, it slices into clean, bouncy squares.
Why You'll Love Butter Mochi
- That chew, soft and bouncy in the middle like mochi, with caramelized, crispy edges.
- No mixer, just two bowls and a whisk.
- Potluck-proof, it travels well, feeds a crowd and tastes even better the next day.
What Is Butter Mochi?
Butter mochi is a much-loved Hawaiian potluck and bake sale dessert. It borrows mochiko from Japanese mochi and coconut milk from island baking, then bakes it all in a pan like a big bar cookie.
The result is somewhere between a coconut custard and chewy mochi. The first time I tasted it, I couldn't stop picking at the crunchy edge pieces, and they're still my favorite part.
Step-by-Step Photos
Here's how it comes together. Exact amounts, times and temperatures are in the recipe card below.
Tips for Success
- Use mochiko, not regular rice flour. Butter mochi needs sweet (glutinous) rice flour for its chew. Plain rice flour bakes up dry and crumbly. The 1-pound box is exactly the amount you need.
- Use a metal pan. Metal gives you those crisp, caramelized edges, which are the best part. In glass, drop the oven to 325°F and expect to bake a little longer.
- Bake it dark. A pale butter mochi is gummy inside. Wait for a deep golden-brown top and edges that pull away from the sides. That color is flavor.
- Cut with plastic. A plastic knife glides through the sticky middle. A buttered metal knife works too; wipe it between cuts.
- It's even better tomorrow. The texture settles overnight and the coconut flavor gets stronger. I bake mine the evening before a potluck and cut it in the morning.
Hawaiian Butter Mochi
24
squares10
minutes1
hour5
minutes245
kcal1
hour15
minutesA one-bowl Hawaiian classic: sweet rice flour (mochiko), coconut milk, butter, eggs and sugar baked in a 9×13 pan into bouncy, chewy, custardy squares with crisp, caramelized edges. Naturally gluten-free.
Ingredients
1 box (16 oz), about 3 cups mochiko (sweet glutinous rice flour)
2 cups granulated sugar
2 teaspoons baking powder
1/2 teaspoon salt
2 cans (13.5 oz each) full-fat coconut milk
4 large eggs
1/2 cup (1 stick) unsalted butter, melted and slightly cooled
2 teaspoons vanilla extract
1/2 cup sweetened shredded coconut (optional)
Directions
- Heat the oven to 350°F. Butter a 9×13-inch metal baking pan.
- In a large bowl, whisk the mochiko, sugar, baking powder and salt so there are no lumps.
- In another bowl, whisk the coconut milk, eggs, melted butter and vanilla until smooth. Pour into the dry ingredients and whisk until the batter is completely smooth and pourable, about 1 minute.
- Pour into the pan and tap it on the counter to pop any air bubbles. Sprinkle with the shredded coconut, if using.
- Bake for 60 to 70 minutes, until the top is deep golden brown, the edges have pulled away from the pan and the center springs back when pressed. A toothpick should come out clean or with a few sticky bits, not wet batter.
- Cool completely in the pan, at least 2 hours, before cutting. Cut with a plastic knife or a buttered knife into 24 squares.
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Easy Variations
- Chocolate butter mochi: whisk 1/3 cup unsweetened cocoa powder into the dry ingredients.
- Ube butter mochi: add 1 tablespoon ube extract with the vanilla for a purple, vanilla-nutty version.
- Matcha: whisk 2 tablespoons matcha powder into the dry ingredients.
- Lighter coconut: swap one can of coconut milk for 1 1/2 cups whole milk for a milder flavor.
More Desserts to Try
If you love the chew, try a mochi donut next. For more ideas, browse my Asian desserts and Filipino desserts, or bake another coconut favorite, impossible coconut pie.
Frequently Asked Questions
What is Hawaiian butter mochi?
Butter mochi is a Hawaiian baked dessert made with mochiko (sweet rice flour), coconut milk, butter, eggs and sugar. It's a mix of Japanese mochi and a custardy coconut cake: chewy and bouncy inside with crisp, golden edges, cut into squares like a bar.
Can I use regular rice flour for butter mochi?
No. Regular rice flour doesn't have the sticky starch that gives mochi its chew, so the cake turns out dry and gritty. Use sweet or glutinous rice flour, often sold as mochiko. Despite the name, it contains no gluten.
Why is my butter mochi gummy?
It was underbaked or cut while warm. Bake until the top is deep golden brown and the edges pull away, usually 60 to 70 minutes at 350°F, then let it cool completely, at least 2 hours, before slicing.
Does butter mochi need to be refrigerated?
Keep it covered at room temperature for up to 2 days. After that, refrigerate it for up to 5 days. It firms up in the fridge, so let a square come to room temperature or warm it for 10 seconds in the microwave.
Can I freeze butter mochi?
Yes. Wrap squares individually in plastic wrap, then put them in a freezer bag for up to 2 months. Thaw at room temperature for about an hour and they come back soft and chewy.
