In a small saucepan, combine dried cranberries, water, orange zest, ginger, cinnamon, and salt. Bring to a gentle simmer over medium heat and cook for about 5–7 minutes, until the cranberries soften and the mixture turns a rich reddish color.
Pour the mixture through a fine mesh strainer into a heatproof bowl, pressing to extract as much liquid as possible. Set the cranberry solids aside (don't discard them) — you should have a tart, flavorful cranberry-orange concentrate.
Return the cranberry concentrate to the saucepan. Add white chocolate chips, sweetened condensed milk, and maple syrup. Heat on low, whisking constantly, just until the chocolate melts and the mixture looks smooth (do not boil).
Remove from heat and stir in vanilla extract and lemon juice. Stir to combine, then let the sauce cool for 10–15 minutes before transferring to a glass jar or squeeze bottle.
Store the reserved cranberries in an airtight container in the fridge for up to two weeks. Add them to yogurt, oatmeal, baked goods, or ice cream.