In a mixing bowl, combine the rice flour and arrowroot flour.

Add the water and stir until smooth, then add the coconut sugar.

Stir until the sugar dissolves, then strain the mixture through a fine sieve and set aside.

For the coconut topping: In a mixing bowl, combine the rice flour, granulated sugar, and salt.

Add the coconut milk and mix well, then strain through a fine sieve and set aside.

Prepare small microwave-safe cups. Stir the cake batter and pour it into the cups, filling each about halfway. Cover with lids.

Microwave for 3 minutes. Remove the lids.

Stir the coconut topping and pour it over the cakes, leaving a little space at the edge. Cover and microwave on high for 2 minutes until the coconut topping is set and glossy.

Let cool, then remove from the molds and serve, or serve directly in the cups.