Preheat the oven to 180°C/Gas Mark 4.
Beat the eggs with the almond milk, olive oil, sugar, a pinch of salt and the vanilla.
In a bowl, mix the brown rice flour, cornflour and baking powder. Add to the bowl of liquid ingredients and stir until the batter is smooth.
Pour about a half the mixture into a baking pan lined with parchment paper. If you have a baking tin with a rounded out middle, use this.
Mix the cocoa powder into the leftover dough. Pour over the first half of the mixture. Add, if desired, chopped almonds or hazelnuts. Bake for about 25-30 minutes, until a toothpick comes out clean. Sieve over a little icing sugar before serving.
Bake for about 25-30 minutes, until a toothpick comes out clean. Sieve over a little icing sugar before serving.