01 - Whisk together the eggs, egg yolks, sugar, pink lemon juice, and zest in a medium heatproof bowl until completely smooth and well combined.
02 - Position the bowl over a saucepan of simmering water, ensuring the bowl bottom does not contact the water surface.
03 - Cook while whisking continuously for 8-10 minutes until the mixture reaches 170°F and coats the back of a spoon.
04 - Remove from heat and whisk in the butter pieces one at a time until each piece melts completely and the curd achieves a silky consistency.
05 - Stir in raspberry juice or natural food coloring if a deeper pink hue is desired.
06 - Pour the curd through a fine-mesh sieve into a clean bowl to remove zest and any cooked egg particles.
07 - Allow to cool completely before transferring to sterilized jars. Refrigerate for minimum 2 hours to set properly. Stored curd remains fresh for up to 2 weeks.