Grate the almond paste on the large holes of a box grater, or cut it into small pieces.
Combine the almond paste, sugar, egg white and vanilla in the bowl of a mixer and mix on low speed for 45 seconds. Mix on medium speed for 30 seconds, scrape down the bowl and then mix for an additional 30 seconds.
Wrap the dough in plastic wrap and refrigerate until cool, about 1 hour.
Line a baking sheet with parchment or foil.
To shape the pastries, put the dough on a cutting board and use the palms of your hands to roll into a rope 18 inches long.
Cut the rope into twelve 1 1/2-inch pieces and roll them into 2-inch logs.
Carefully break up the sliced almonds into smaller pieces. Applying a little pressure, roll the pastries one at a time in the almonds to coat them. They should be about 3 inches long by the end.
Transfer the pastries to the prepared baking sheet and curve each one into a crescent shape. Bake until very lightly browned, 10 to 12 minutes. Cool to room temperature.
Melt the chocolate in a small bowl placed over simmering water. Add the coconut oil if you prefer a thinner dipping chocolate.
Dip each end of the pastries in chocolate and return baking sheet. Refrigerate to set the chocolate.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.