Return the strained cranberry mixture to the saucepan and add the sugar, eggs, egg yolks, butter, vanilla, and orange liqueur (if using) to the pan and give everything a good stir. Heat gently over medium-low heat, stirring constantly, until the mixture thickens and registers 170°F on an instant read thermometer (about 8-9 minutes). Immediately strain through a fine mesh sieve into a bowl and pour into the prepared crust. Bake (still at 350°F) until the curd is set (it should jiggle but not slosh), about 10 minutes.