Sweet and Sharp Sponge Drops
Preheat the oven to 190°C (170 fan) | 375°F | gas 5 and line two large baking trays with non-stick baking mats.
Combine the flour, baking powder, sugar, butter, eggs and cinnamon in a bowl and whisk together for 2 minutes or until smooth.
Spoon the mixture into a piping bag fitted with a large plain nozzle and pipe 18 walnut-sized domes onto each tray.
Transfer the trays to the oven and bake for 10 - 15 minutes. The mixture should spread a little whilst cooking and the cakes will be ready when springy to the touch. Leave the cakes to cool on the tray then lift them off with a palette knife.
Mix the lime curd with the food colouring until evenly coloured then sandwich the cakes together in pairs.