Preheat your oven to 350 degrees.
Line a baking sheet with parchment paper or aluminum foil and spray with baking spray. Set aside.
In a large mixing bowl grate the almond paste with a large cheese grater. Add the sugar, cornstarch, baking powder, zest and limoncello. Beat with an electric mixer until smooth. Add in the beaten egg white and mix with the mixer until fully incorporated and smooth.
Using a small ice cream scoop or two teaspoons drop a small dollop of dough, about 2 teaspoons into confectioners sugar. Spoon some confectioners sugar. Spoon some sugar over the dough so it is evenly coated with sugar before you attempt to roll it. Roll into little balls. Place on prepared baking sheets 2 inches apart. Bake for 10-12 minutes. The cookies may be soft out of the oven but will firm up as they cool. Avoid moving them from the baking sheet until cool.