- In a bowl, combine the flour, sugar, and salt. Make a well in the flour. Add the egg yolks and oil and stir.
- Gradually add the milk and beer, beating with an electric mixer until the batter is smooth. Stir in the rum. Set aside.
- In another bowl, beat the egg whites with an electric mixer until semi-firm peaks form. Fold the egg whites into the batter and refrigerate for about 2 hours.
- In a 23-cm (9-inch) skillet, lightly brushed with butter, cook the pancakes, one at a time, with about 125 ml (1/2 cup) of batter for each, browning on each side. Place the pancakes on a warm plate as you go.