• Heat the oven to 350°F. Lightly coat a 9x13-inch baking pan with butter or baking spray.

Prepare Strawberries

• Blend hulled strawberries into a puree, then add 1 cup of milk to the blender a few tablespoons at a time and keep blending until smooth.
• Pour strawberry milk purée through a fine mesh sieve to remove any pieces of fruit and seeds. Press on solids to extract as much strawberry milk as possible. You will have about 2 cups of purée. Discard pulp and seeds or use for something else.

Make Strawberry Mochi Cake

• Whisk together 4 large eggs, 1½ cups sugar, strawberry purée milk and remaining milk, and 2 teaspoons vanilla extract in a large bowl just until well combined, about 2 minutes. Try not to beat or whip too much air into the batter.
• In a sieve directly over the bowl with the liquid ingredients, sift together all the mochiko, 2 teaspoons baking powder, and ½ teaspoon sea salt directly into the liquid ingredients.
• Stir dry ingredients into liquid ingredients until well incorporated. You do not need to worry about overmixing because mochiko does not have gluten.
• Add the melted butter and mix until fully combined. The batter will be liquidy.
• Pour the Strawberry Mochi Cake batter into the prepared baking pan. Tap the baking pan against the countertop to level out the batter and pop any air bubbles. If you are using sesame seeds, evenly sprinkle in a thin layer over the top of the batter.
• Bake the Strawberry Butter Mochi Cake for about 1 hour, or until the butter mochi no longer wiggles in the center when you shake the pan.
• Place the pan on a wire rack and run a knife with a thin blade around the edge of the pan. Let the Strawberry Mochi Cake cool in the pan completely, about 1 hour. Tip the Strawberry Mochi out on to a cutting board to slice and serve or wrap for storage.