Ingredients

• Cooking spray

• 1 (14- x 12-inch) banana leaf piece

• 1 1/4 cups sweet rice flour (such as Koda Farms Mochiko Sweet Rice Flour)

• 1 1/4 cups glutinous rice flour (such as Erawan)

• 2 1/2 teaspoons baking powder

• 1 teaspoon kosher salt

• 1 cup granulated sugar

• 1 cup very ripe mashed bananas (from 2 to 3 medium bananas) 

• 3/4 cup well-shaken and stirred unsweetened coconut milk

• 1/2 cup unsalted butter (4 ounces), melted

• 1 teaspoon vanilla extract

• 2 large eggs, at room temperature