How to Make It
Preheat the oven to 375° and position the racks in the upper and lower thirds of the oven. Line 2 baking sheets with parchment paper. In a food processor, process the almond paste, sugar and salt until very finely chopped. Add the amaro digestif and egg whites and process until smooth. Transfer the batter to a pastry bag fitted with a 1/2-inch plain tip. Pipe scant 1-inch mounds of batter onto the prepared baking sheets, 2 inches apart. Sprinkle generously with pearl sugar.
Bake the cookies for about 15 minutes, until risen and lightly cracked; shift the pans from top to bottom and front to back halfway through baking. Let the cookies cool completely on the paper (the cookies will stick to the paper). Invert the paper onto a work surface and carefully peel it off the backs of the cookies. Repeat with the remaining batter.
Pearl sugar is available online at kingarthurflour.com.