These Copycat Thin Mints taste just like real Girl Scout Cookies! Crisp melt-in-your-mouth mint-chocolate wafer cookies are coated in a thin layer of a chocolate glaze-like coating.
Make the thin mint cookie dough: in the bowl of a stand mixer (or in a large mixing bowl) cream together the shortening and sugar. Add oil, corn syrup, and mint extract, and mix until combined. Then add the cocoa powder, baking soda, cornstarch, and salt. Finally, add the flour and mix on low speed until just combined, then add the water.* Form the dough into a ball, flatten it slightly into a disk shape, and wrap it in plastic wrap. Refrigerate for at least 1 hour or overnight.
Stamp and bake cookies: preheat the oven to 325 °F. Roll out the dough on a sheet of parchment paper to ¼ inch even thickness.* Using a small scalloped cookie cutter, stamp circles out of the dough. Use an icing spatula (or similar) to carefully transfer the cookies to a sheet tray lined with parchment paper, spaced evenly apart with about 2 inches in between.* Bake for 9-10 minutes and let cookies cool on the tray before dipping.
Make the chocolate coating: combine cocoa, coconut oil, powdered sugar, and salt in a medium mixing bowl. Then add the hot water and whisk until totally smooth. Adjust the consistency with extra water if needed (it should be pretty thin).
Dip the cookies into the chocolate coating one at a time. Use a spoon or spatula to completely cover the cookie and wipe off excess chocolate. Then use a fork to carefully transfer the cookies to a wire rack to dry and allow the coating to harden for at least 1 hour.*
Notes
The dough is very crumbly, like wet sand, but holds together when pressed.
If the dough is sticking, coat the parchment, rolling pin, and cookie cutter with a little bit of flour. (The dough is pretty oily though so it shouldn’t stick, even without flour.)
Optional tips: Poke dots in the cookies with a toothpick or skewer for lookalike! And place the tray of unbaked cookies in the freezer or refrigerator for 30 minutes before baking to help hold their shape.
About 20 minutes after coating the cookies in chocolate (when they are partially set) use a fork to gently shift the cookies on the wire rack. This will prevent them from sticking to the rack and breaking once the chocolate is fully hardened.