Use a food processor or blender to pulse whole cookies into crumbs. Once you have 2 cups of fine crumbs add the brown sugar and melted butter to the food processor and mix together until fully combined.
Press the crumb mixture into the bottom and sides of a 9-inch tart pan. Bake for about 7-8 minutes, until it just barely begins to brown. Allow to cool completely before adding the filling.
In a medium saucepan combine the cranberries, both zests, both juices, and sugar. Cook over medium-low heat until simmering. Cook until the cranberries have burst and the sugar has fully dissolved for about 10 minutes. Remove from the heat.
In a small bowl combine the whole eggs and egg yolks. Temper the eggs by slowly whisking in a cup of the warm cranberry mixture. Once the eggs are warmed, add the egg mixture into the pot and whisk until combined.
Cook over low heat for about 10 minutes, until the mixture has thickened and is bubbling. Remove from the heat and whisk in the softened butter and a dash of salt.
Pour the curd into a bowl and cover with plastic wrap touching the surface of the curd so it doesn’t create a film as it cools.
Let the curd chill in the fridge for at least 3 hours before pouring into the chilled crust. Smooth the top and garnish with sugared cranberries and fresh rosemary before serving.