Preheat oven to 375 F, line bottom of a tart pan with parchment paper. Lightly grease sides of the tart pan with butter. I use a pastry brush dipped in some of the melted butter. In a food processor, pulse gringersnaps into a course sand like texture. Add cold, cubed butter and process until it just comes together. Press into prepared tart, starting with the sides and working across the bottom to the center of the pan. Chill in the fridge for 15-20 minutes. Line the crust with a piece of parchment paper, cut the diameter of the tart pan. Line with pie weights, rice or dried beans. Bake for 18-20 minutes. Remove from oven and place on a cooling rack until ready to be filled with the curd. Reduce heat to 350F.
Heat cranberries and orange juice in a sauce pan over low-medium high heat until cranberries begin to soften slightly and split. Strain through a mesh strainer, discarding the skins and returing the cranberry mixture to the same sauce pan. Add all remaining ingredients to the sauce pan with the cranberry mixture. Gently, but throughly stir together. Heat over low-medium heat until the mixture thickens, about 9 minutes.
As soon as the mixture thickens, strain through the same mesh strainer, into another bowl or container. Pour into par-baked crust and return to the oven. Bake at 350F for 10-12 minutes, or until the curd sets with a slight giggle. Remove from oven and cool on a cooling rack to room temperature, about an hour. At this point, the tart can go into the fridge to chill or can be served at room temperature.