Preparation Put oven rack in middle position and preheat oven to 350°F. Whisk together mochiko, sugar, baking powder, and salt in a large bowl. Whisk together coconut milk, eggs, butter, and vanilla in another bowl. Add coconut mixture to flour mixture, whisking until batter is combined. Pour batter into an ungreased 13- by 9-inch baking pan, smoothing top, and bake until top is golden and cake begins to pull away from sides of pan, about 1 1/2 hours. Cool cake completely in pan on a rack, about 2 hours. Cut mochi into 24 squares before serving. Cooks' note:Mochi keeps, covered and chilled, 3 days. *Available at Asian markets and Uwajimaya (800-889-1928; uwajimaya.com).
Preparation Put oven rack in middle position and preheat oven to 350°F. Whisk together mochiko, sugar, baking powder, and salt in a large bowl. Whisk together coconut milk, eggs, butter, and vanilla in another bowl. Add coconut mixture to flour mixture, whisking until batter is combined. Pour batter into an ungreased 13- by 9-inch baking pan, smoothing top, and bake until top is golden and cake begins to pull away from sides of pan, about 1 1/2 hours. Cool cake completely in pan on a rack, about 2 hours. Cut mochi into 24 squares before serving. Cooks' note:Mochi keeps, covered and chilled, 3 days. *Available at Asian markets and Uwajimaya (800-889-1928; uwajimaya.com).