Soak 3 tablespoons of raisins in 3 tablespoons of water for at least 2 hours.
Separate 3 large eggs. Beat the yolks with ¼ cup of sugar and 1 teaspoon of vanilla extract until pale. Beat in 1⅓ cups of milk, 1⅛ cups of all-purpose flour, and ⅛ teaspoon of salt.
Whisk the egg whites to stiff peaks. Fold gently into the batter, leaving a few white streaks.
Measure 3 tablespoons of unsalted butter. Melt two-thirds in a 12in / 30cm nonstick skillet over medium heat. Pour in the batter and cook for 1-2 minutes. Scatter with the drained raisins.
Cover and cook for 7-8 minutes, until the underside is lightly browned. Cut into quarters, turn and cook until the other side is browned and the center set.
Tear into bite-sized pieces. Add the remaining butter and 1 tablespoon of extra sugar. Toss until the sugar melts. Dust with icing sugar and serve hot.
