lemon curd 
(British also lemon cheese)
noun [mass noun]
A thick conserve made from lemons, butter, eggs, and sugar: [as modifier]: lemon curd tarts...
- This consisted of a single warmed scone, a pot of lemon curd and one of clotted cream.
- Dessert is fresh fruit, pound cake with lemon curd and cream, and assorted sweet bars.
- Cut the sponge cake into thin slices then spread each one generously with the orange or lemon curd.