Combine the eggs, egg yolks, 1/2 cup turbinado sugar, the half-and-half, flour, Grand Marnier, vanilla and salt in a blender. Pulse until the sugar has dissolved and the batter is smooth, about 1 minute. Let sit at room temperature, 30 minutes.
Meanwhile, position a rack in the upper third of the oven and preheat to 425 degrees F. Butter the bottom and side of an 11-inch ceramic tart pan or pie plate and set on a baking sheet. Toss the cranberries with 5 tablespoons turbinado sugar in a small bowl; spread in the bottom of the prepared tart pan. Bake until the mixture starts to caramelize, about 20 minutes. Remove from the oven and reduce the temperature to 375 degrees F.
Carefully pour 1 cup of the prepared batter into the hot pan and let sit 5 minutes, then pour in the remaining batter. Sprinkle the remaining 3 tablespoons turbinado sugar on top. Bake until puffed and almost set, about 30 minutes. Transfer to a rack and let cool 20 minutes. Dust with confectioners' sugar.