In saucepan set over medium heat, combine prune and orange juice. Heat for 1 minute or until steaming. Add prunes, remove from heat, cover and let stand for 10 minutes. 

In bowl, whisk together flour, baking powder and salt. In separate bowl, whisk together milk and eggs. Whisk into dry ingredients until smooth.

Remove prunes with slotted spoon and fold into batter with orange zest. 

Bring prune-orange juice mixture to simmer over medium heat. Simmer for 7 to 8 minutes or until reduced by half and syrupy. Reserve for topping. 

Melt half the butter in skillet set over medium-high heat. Drop batter by scant 1/4 cup into pan. Cook until bubbles form, about 1 to 2 minutes. Repeat with remaining butter and batter. 

Serve pancakes with a dollop of yogurt and a drizzle of prune orange syrup. Top with raspberries and mint, if desired.