You will need 23 cm ( 10") cake tin and set the oven at 180C (350 F) deg for 15-20 minutes.
Put the rice and sugar into the food processor and buzz till smooth.
Add the eggs, vanilla, almond meal, cocoa powder and baking powder .
Puree till combined.
Pour into cupcake papers 3/4 full, or into a 23 cm ( 10") cake tin and bake at 180 C(350 F) deg for 15-20 minutes for cupcakes and 40-45 minutes for a 23 cm. A skewer should come out clean when the cake is tested.
Heat the cream in a jug or a sauce pan till warm but not boiling. Take off the heat and add the chocolate . Stir till melted. Cool . Beat in an electric mixer until light and fluffy. Pipe or spread onto the cakes.
I spread a layer of salted caramel on the cake before ganaching it.
Puree till smooth. This cake has no gluten so won't get tough.