Preheat oven to 350. Grease a 9X13 baking pan.
In a large mixing bowl, whisk together mochiko flour, sugar, baking powder, matcha powder and salt.
In a separate bowl or large measuring cup (4 cup capacity), beat eggs, then add coconut milk,evaporated milk and melted butter.
Carefully pour the wet ingredients over the mochiko flour mixture and whisk until mixture is smooth and uniform in texture.
Pour batter into greased 9X13 pan. Carefully smooth out the top.
Bake for 90 minutes, until top is golden brown and the cake begins to pull away from the sides of the pan.
Allow cake to cool for about 30 minutes on a rack, and then carefully flip it out and cut into 24 squares, or the size of your choice. Can store mochi cake for three days, covered.