Preheat the oven to 350°F. Coat a 9x13 baking pan with butter, then sprinkle a light dusting of cocoa powder over the butter. Set aside.
In a medium bowl whisk together the cocoa powder and the boiling water. If the mixture is too thick, add in 1 tablespoon of hot water until it looks like creamy chocolate frosting. Once well combined, allow the mixture to cool for about 2-3 minutes. Once cooled, whisk in the milk until smooth and creamy, then set aside. (The mixture should be similar to very chocolate hot cocoa, or dark chocolate milk. Be sure to whisk until all of the cocoa powder is dissolved.)
½ cup unsweetened cocoa powder, ⅓ cup boiling or very hot water, ⅔ cup milk
In a medium bowl, whisk the flour, baking soda, and salt together. Set aside.
2 cups all-purpose flour, ½ teaspoon baking soda, ¼ teaspoon kosher salt
In a large bowl, with a hand mixer, beat the butter and sugar, mixing until it is blended together and looks creamy. Continue mixing and add in the vanilla and the eggs.
1 cup unsalted butter, 1½ cups granulated sugar, 1 teaspoon pure vanilla extract, 3 large eggs
Add the cocoa mixture to the sugar mixture, mixing on medium speed until it is all well combined together. Add in the flour mixture in batches, while mixing on low to medium speed. Once the batter is smooth and creamy, pour it into the prepared pan and spread evenly.
Bake for about 25-30 minutes, until a toothpick comes out clean or the top of the cake springs back when touched. Remove from the oven and allow to cool.
Once the cake has cooled, break it into pieces until it is a fine crumble. Stir in the frosting, mixing until the crumble forms into a small ball and sticks together.
16 ounces pre-made chocolate frosting
Scoop into 1½ inch balls and roll into a round shape. Place the shaped balls into a large bowl and refrigerate for about 30 minutes.
In a medium microwave-safe bowl, melt the chocolate. Place the pop stick into the chocolate, just covering the top of the stick before inserting into the cake pop this helps hold the cake pop on the stick when you are dipping). Dip the entire ball of cake into the chocolate, until it is completely covered. Tap the middle of the stick onto the edge of the bowl so the excess chocolate drips back into the bowl. Allow the chocolate to set.
10 ounces melting chocolate