2 large egg whites -- room temperature
pinch salt
2/3 cup sugar -- sifted
1 tsp lemon zest -- finely grated
1/4 tsp vanilla extract

Preheat oven to 250° (F) Cover 2 baking sheets with parchment or foil.

Beat egg whites with salt until soft peaks form. Add sugar very slowly, beating well between additions, until egg whites are stiff but not dry.

Fold in lemon zest and vanilla.

Drop by teaspoonfuls onto the baking sheets or pipe small kisses with a pastry bag fitted with a 1/2-inch star tip.

Bake until dry, but not brown, 40 to 45 minutes. Cool 2 to 3 minutes before removing from baking sheets.