01 - In a medium saucepan, combine cranberries, sugar, orange juice, orange zest, water, vanilla extract, and salt.
02 - Bring the mixture to a gentle boil over medium heat, stirring occasionally.
03 - Reduce heat and simmer for 15 to 20 minutes, stirring often, until cranberries burst and the jam thickens. Mash cranberries with a spoon for a smoother texture if preferred.
04 - Remove from heat and allow to cool to room temperature; the jam will thicken further as it cools.
05 - Toast bread slices until golden and crisp using a toaster or grill pan.
06 - Spread unsalted butter on warm toast if desired.
07 - Generously spoon cranberry jam over the toast and serve immediately.