Mix flour, sugar, and cold butter in a bowl until crumbly texture forms.
Add egg yolk and cold water, then form a soft dough.
Chill dough for 20–30 minutes in the refrigerator.
Roll out dough and place into a tart pan evenly.
Prick base with a fork and pre-bake at 180°C (350°F) for 10–12 minutes.
Mix orange marmalade with orange juice and lemon juice until smooth.
Pour filling into pre-baked crust and spread evenly.
Bake again for 10–15 minutes until glossy and slightly bubbling.
Let the tart cool completely before slicing and serving.