Heat oven to 180C/fan 160C/gas 4. Put the flour, sugar and butter into a food processor. Whizz until the mixture forms crumbs, then pulse a little more until it forms a ball.
Spread a large sheet of baking parchment over the work surface and turn the dough onto it. Dust with a little flour, then roll out to about the thickness of two £1 coins. Stamp out 24 rounds using a 5cm round fluted cutter, then cut out the middles with the end of a piping nozzle. Carefully peel the rest of the mixture away from the stamped shapes. Lift onto baking sheets and bake for 10 mins until pale golden. Cool on a wire rack.
Put the lemon curd into a bowl with 2 tbsp boiling water and mix until smooth. Sieve in 175g of the icing sugar; stir together to make a smooth icing. Put the strawberry fruit spread in another bowl and add 2 tsp boiling water, mix, then sieve in the remaining icing sugar.
Spoon the lemon icing over the biscuits, then drizzle or pipe over the pinky icing. Leave to set for at least 20 mins. Will keep for up to 2 days in an airtight tin, longer if left un-iced.