To make the cake:

1. Preheat the oven to 350 degrees, and line a 9 x 9 square pan with parchment paper. Alternatively, use butter or baking spray to grease the insides of the pan. Set aside.
2. Stir the vanilla extract and cocoa powder into the hot coffee, whisking to dissolve well. Set aside.
3. In a large mixing bowl, combine the sugar, salt, baking soda, egg and egg yolk. Whisk well for one minute, the mixture should be more pale and thick.
4. Add the buttermilk and oil, and mix for another minute. Add the flour and whisk well for 2 minutes. The batter should thicken up a bit more as you mix in the flour.
5. Pour in the coffee/cocoa/vanilla mixture and the melted chocolate and gently mix for one minute until well combined. Use a spatula to scrape the sides and bottom of the bowl and make sure everything is incorporated.
6. Pour the cake batter into the prepared 9 x 9 pan and bake for 35 minutes. The cake should be crowned in the center with no wrinkles, use a toothpick to test for doneness. If the toothpick comes out clean, then the cake is ready.
7. Allow the cake to cool completely before chilling overnight. The cake must be cold before assembling the cake pops.
8. Crumble the cold cake into the bowl of a stand mixer and beat with the paddle attachment for 30 seconds to create uniform crumbs. You should have about 7 cups of crumbled cake. Add a tablespoon of frosting to the crumbs and beat for 30 seconds to combine.
9. Test the cake/frosting mixture to see if it will hold together. If you are able to roll it between your hands like cookie dough without it breaking apart, it’s ready. Add another tablespoon of frosting if necessary, but NO MORE than that.
10. Use a medium cookie scoop to form each cake ball. Scrape the cake mixture into the scoop so that it overflows, then press the flat side of the scoop against the inside of the bowl to pack it and level it off.
11. Roll each packed ball between your palms to smooth it out, and repeat for the remaining cake mixture. Allow the formed cake balls to chill for an hour before adding the sticks.

To assemble and finish the cake pops:

1. Melt the 12 oz of chopped chocolate in the microwave for 30 seconds on full power. Stir well and heat for another 30 seconds. Stir again. Repeat once or twice more, stirring between each 30 second interval to distribute the heat and completely melt the chocolate. If you’re working with coating instead of actual chocolate, keep a close eye on them during the melting. The coating is much more prone to overheating and seizing up than chocolate.
2. If the coating does overheat and seize, add a few more ounces of coating and stir vigorously to cool everything down. The coating should be pourable again within 10 minutes.
3. Add the melted chocolate to a tall, more narrow container, such as a measuring cup. Dip each treat stick about 2 inches down into the chocolate before pressing the stick halfway down into the cake ball. This will form a small “button” where the stick meets the cake ball. Repeat for the remaining cake balls.
4. Beginning with the first cake pop you added a stick to, dip each cake pop in the melted chocolate. Be sure to totally submerge the cake pop just above the chocolate button, so that the chocolate goes up onto the stick a little bit.
5. Swirl and tap each coated cake pop on the edge of the measuring cup to get rid of any excess chocolate.
6. Invert each freshly dipped cake pop onto a block of floral foam or cardboard box, pressing the free end of the stick into the foam to securely hold it in place while it dries. Repeat for the remaining cake pops. If you are using sprinkles, add them to each cake pop immediately after dipping, before the chocolate dries.
7. Allow the completed cake pops to chill for an hour before serving.