For the cookies: Cream the butter with the powdered sugar. Add the egg and vanilla and mix to combine. Add the flour, cocoa powder and salt, and mix together until the dough comes together. Place plastic wrap on the surface of the dough and refrigerate for 2 hours.
Preheat the oven to 375 degrees F. Line baking sheets with baking mats or parchment.
Roll out the cookie dough and cut out the cookies using a rectangular cookie cutter, re-rolling the scraps in order to use as much of the dough as possible. Place the cookies onto the prepared baking sheets. Bake for 7 to 9 minutes, in batches if necessary, being careful not to burn. Cookies will remain the same general size and shape after they bake.
Remove from the oven and place the cookies on a cooling rack. Allow them to cool completely.
Melt the almond barks in separate bowls in the microwave. Dip half of each cookie into the white almond bark and half into the chocolate bark. Immediately sprinkle or press toppings from the Dipping Bar over both sides of the cookies. Gently set on parchment paper or another nonstick surface and allow to cool before serving.