For the babàs:

• 1 tablespoon active dry yeast
• 1 tablespoon granulated sugar
• 1½ cups all-purpose flour, plus extra
• 2 eggs
• 4 tablespoons (½ stick) unsalted butter, softened, plus extra
• 1 teaspoon vanilla extract
• Zest of ½ lemon

To finish:

• ½ cup granulated sugar
• ½ cup dark rum
• ¾ cup heavy cream, whipped with 2 tablespoons confectioners' sugar

Prepare the babàs: Preheat oven to 350°. Place the yeast and sugar in the bowl of a mixer fitted with the dough hook attachment. Add ¾ cup warm water, and mix well. Set aside to proof for 10 minutes, and add the flour, eggs and butter. Mix well, and add the vanilla and lemon zest. Cover with plastic wrap, and set aside to rise until it doubles in volume, about 30 minutes. Butter and flour 16 popover molds or muffin tins. Punch the dough down. Fill each mold halfway with the dough, and set aside for 30 minutes. Place the babàs in the oven, and bake until well-browned, about 20 minutes.

Meanwhile, combine the sugar, rum and 1½ cups of water in a saucepan. Bring to a boil, and cook for 10 minutes. Remove the babàs from the oven, and unmold. Brush them with the rum glaze, and set aside for 10 minutes. Place the whipped cream in a pastry bag fitted with a star tip. Cut the babàs in half, and pipe rosettes of whipped cream into each babà.