In large bowl of an electric mixer, beat almond paste, granulated sugar, and lemon peel until mixture resembles very fine crumbs.
Gradually drizzle in egg whites, blending well after each addition, until batter just barely holds soft peaks.
Stand a pastry bag fitted with a plain tip (#6 size) in a drinking glass; then fill it with batter.
Pipe onto baking sheets lined with parchment paper or brown wrapping paper, making 1 1/4-inch circles spaced 2 inches apart.
Sift powdered sugar generously over each round to cover completely.
Let unbaked cookies stand, uncovered, until they're dry enough to develop a slight crust (at least 8 hours or up to 24 hours).
Pinch top of each round simultaneously with thumb and forefinger of both hands, making 4 indentations.
Bake on center rack in a 350Â° oven for 12 to 15 minutes or until richly golden.
Slide parchment and macaroons off baking sheet onto a damp towel and let cool.
Run a spatula under cookies to loosen from parchment.