Recipe from Simon & Alison Holst’s Gluten-free Baking
• 1 cup tapioca flour
• 1 cup rice flour
• 1/2 cup icing sugar
• 125g butter
• 2 tablespoons water
• 1 1/2 cups sugar
• Thinly peeled rind of half a lemon
• 3 large eggs
• 1/4 cup lemon juice
• 1/4 cup custard powder
• Icing sugar to dust
• Preheat oven to 160°C/320°F. Line a 18-28cm tin with baking paper, making sure it covers all sides.
• For the base, measure the flours, icing sugar and cubed butter into a food processor. Process until butter is mixed through, then drizzle in the water while the processor is still running.
• Tip mixture into the lined pan and press down firmly and evenly.
• Bake for 15-20 minutes until firm and just beginning to brown.
• For the topping, rinse and dry the food processor, then process the sugar and lemon rind until the rind is very finely chopped.
• Add the eggs, lemon juice and custard powder, and process until smooth.
• Pour over partly cooked base, then bake for a further 30 minutes, or until the top is lightly browned and the centre does not wobble when the pan is jiggled.
• When the slice has cooled, cut into squares and dust with icing sugar. Serve with Greek-style yoghurt or whipped cream.