Zest one orange and juice all three oranges. Combine cranberries, ¾ cup orange juice, 1 teaspoon grated zest, and peppercorns in a saucepan over medium-high heat. Cook, stirring occasionally, until cranberries burst and mixture becomes thick and jammy, about 10 minutes.
Transfer cranberry mixture to a food processor and purée.
Strain cranberry mixture through a fine-mesh sieve back into saucepan; press on solids using a wooden spoon or rubber spatula to extract purée. Discard solids. Stir honey, butter and salt into saucepan with purée.
Cook mixture over medium heat until butter is melted and mixture registers 130ºF (54ºC) on an instant-read thermometer, about 5 minutes.
Whisk together eggs and egg yolks in a large bowl. Very gradually whisk cranberry mixture into egg mixture; transfer mixture back to saucepan over low heat and cook, whisking constantly, until mixture is thickened, coats back of a spoon, and registers 170ºF (77ºC) on an instant-read thermometer, about 8 minutes.
Off heat, stir in liqueur then strain through a fine mesh sieve into a bowl. Press a piece of plastic wrap on surface of curd and refrigerate until completely chilled, at least 4 hours (or up to 4 days).
Heat oven to 350ºF (176ºC) with rack set in middle position. Spread cooled curd into cooled crust and smooth. Bake tart until filling is set; 12–15 minutes.
Transfer tart to a wire rack to cool completely. Remove tart from pan by placing on an inverted cup and pressing pan edges down. Set tart on a flat surface, then slide a thin metal spatula between tart and pan bottom; carefully slide tart onto a serving platter. Garnish with desired toppings and serve.