Preheat the oven to 300 degrees F, and line 2 baking sheets with parchment paper. Add the almonds, baking soda, salt and 1 1/2 cups confectioners' sugar to a food processor. Process until finely ground, about 1 minute.
Whisk together the honey, vanilla and egg. Add to the almond mixture and pulse until a stiff dough forms.
Roll tablespoon-sized portions of dough into balls, and coat in the remaining cup confectioners' sugar. Place at least 3 inches apart on the prepared baking sheets.
Bake, rotating halfway through, until cracked and solid to the touch, 18 to 20 minutes. Slide the parchment off the baking sheets and allow the ricciarelli to cool completely before peeling off the paper. Store cookies in a tin or airtight container for up to 2 weeks.