In a medium bowl, combine flour, backing powder, and salt.

In a large bowl, whisk eggs until frothy. Whisk in sugar. Stir in melted butter and vanilla. Fold in flour mixture.

Lightly coat electric pizzelle iron with cooking oil; heat according to manufacture recommendations.

(Or coat non electric pizzelle iron with cooking oil; heat on range top over heat until a drop of water sizzles on the grid. Reduce heat to medium-low).

For each pizzelle: place a slightly rounded tablespoon on pizzelle grid. Close lid.

Bake according to manufacture's recommendations. (If using a non electric iron, bake about 1 minute on each side or until lightly browned).

Transfer warm pizzelle to wire rack; let cool. If desired, sprinkle with powdered sugar.