Roughly chop the prunes. Place all prune jam ingredients into a small pot and bring to a simmer, stirring to combine. Cook until the liquid reduces by about ¼ and becomes a syrup. Whisk the jam together briskly to further thicken. Remove from heat and cool at least to room temperature before serving. Will keep for 1 month in the fridge.
Toast the bread. Smear with a generous helping of ricotta. Spoon the prune jam over the toast and cheese. Garnish with chopped peanuts and the micro basil or basil ribbons. Sprinkle with Maldon salt and chili flakes.