Step 1

Pour confectioner's sugar in a medium saucepan and make a deep well in the center. Add potatoes, butter, vanilla and salt to the well and place saucepan over a large saucepan filled with water that's just about to simmer.

Step 2

Stir mixture with a spatula, gradually adding confectioner's sugar to the mix, until all ingredients are incorporated and melted together into a smooth paste, takes about 5 minutes.

Step 3

Remove from heat and stir in coconut. Shape dough into a ball, then press into a 4-by-5-inch rectangle on a baking sheet or plate. Place in freezer to firm, 20 minutes.

Step 4

Remove baking sheet from freezer and cut rectangle into 20 one-inch squares. Cover tightly with plastic wrap and return to freezer to firm, for 20 minutes.

Step 5

Meanwhile, make your chocolate coating: In a medium microwaveable bowl, melt chocolate squares into a smooth sauce. Whisk in shortening and stir until completely mixed in, about a minute.

Step 6

Place a silicone mat or sheet of wax paper on a clean baking sheet and set aside.

Step 7

Remove squares from freezer and, using a fork, submerge one square at a time into the chocolate coating. Tap off excess chocolate and place on prepared baking sheet. Repeat until all squares are fully coated in chocolate.

Step 8

Place squares on baking sheet in refrigerator to set, about 1 hour.