Combine cranberries, orange zest, orange juice, and honey in a medium-sized saucepan. Cook on medium-low heat, stirring occasionally for about 8 minutes until the cranberries burst. Use the back of a spoon to crush them. Let the mixture cool for 15 minutes.
1 cup cranberries, zest from one small orange, ⅓ cup fresh orange juice, ⅓ cup raw honey
Add the warm but not hot cranberry mixture to a blender and blend thoroughly until smooth. Meanwhile wash the saucepan because you will use it again shortly.
In a small bowl, whisk together the egg and egg yolk.
1 large egg, 1 large egg yolk
Gradually add the warm blended cranberry mixture to the eggs, whisking continuously until fully combined.
Pour the mixture back into the saucepan. Cook on medium-low heat, whisking continuously until the mixture thickens. This takes around 3-5 minutes.
Remove from heat and immediately whisk in butter and vanilla extract.
3 tablespoon unsalted butter, ½ teaspoon pure vanilla extract
Allow the curd to cool and transfer to a sealed container while you proceed to the next step.