Preheat the oven to 350 degrees F. Line a 9-inch by 5-inch loaf pan with parchment paper.
If you would like to add the crumb topping, combine all the topping ingredients in a small bowl and set aside until ready to use.
In a mixing bowl, beat together the eggs, vanilla extract, melted butter, and orange juice.
In a separate bowl, whisk the coconut flour, sugar-free sweetener, baking powder, and sea salt until well blended.
Gradually add the dry ingredients to the wet ingredients, beating until thoroughly combined.
Stir in the orange zest. The batter will become very thick and crumbly.
Toss the cranberries with 2 teaspoons of coconut flour until they are well coated.
Fold the cranberries into the batter until evenly incorporated.
Transfer the batter to the prepared loaf pan, then press it down evenly using your hands or a rubber spatula.
If using, sprinkle the crumb topping evenly over the batter.
Bake on the center rack of the preheated oven for 50 to 55 minutes, or until the bread is golden brown and a toothpick inserted in the center comes out clean.
Let the bread cool for at least 40 minutes before slicing and serving.