2 plantains, cut into 1/2-inch pieces
1 egg
1 cup evaporated milk
2 tablespoons margarine, melted
1 cup all-purpose flour
1 ½ tablespoons white sugar
2 teaspoons baking powder
1 teaspoon vanilla extract
½ teaspoon salt
1 teaspoon butter, or as needed
Heat 1 tablespoon butter in a skillet over medium-low heat; saute plantains until golden brown, about 5 minutes per side. Transfer plantains to a paper towel-lined plate using a slotted spoon. Beat egg in a large bowl until fluffy. Stir milk and margarine into egg; add flour, sugar, baking powder, vanilla extract, and salt. Stir mixture until batter is smooth. Fold plantains into batter. Melt 1 teaspoon butter in a heavy griddle or frying pan over medium heat. Griddle is ready with a drop of water breaks into several smaller balls that dance around griddle. Pour batter, about 1/4 cup per pancake, into hot griddle. Cook until bubbles form and the edges are dry, 2 to 3 minutes. Flip pancakes and cook until browned on the other side, 2 to 3 minutes. Repeat with remaining batter.