- Preheat the oven to 350°F (180°C). Grease an 8-inch (20 cm) square baking pan and line it with parchment paper so that the paper comes up the sides.
- Beat the butter, brown sugar and molasses in a large mixing bowl until smooth, then beat in the egg and ginger.
- In a separate bowl, sift the rice flour, tapioca starch, baking powder, cinnamon, xantham, allspice, salt and cloves and then stir this into the molasses mixture until evenly blended. Measure the boiling water and then stir in the baking soda (it will foam) and stir this immediately into the cake batter (the batter will be fluid). Stir in the raisins and pour this into the prepared pan. Bake the cake for about 50 minutes, or until a skewer inserted in the entre of the cake comes out clean. Allow the cake to cool in the pan, and cut into squares to serve.