Preheat oven to 350°F and lightly grease a 9” cake pan
In a large bowl sift together the flour, Dutch process cocoa powder, baking soda, and salt. Set aside.
In the bowl of a stand mixer, or by hand, in a large bowl beat the sugar, melted butter, egg, and vanilla until thick and creamy.
Pour in the buttermilk and cooled coffee. Mix lightly until just incorporated.
Add all of the dry ingredients and beat on medium until a thick and smooth batter has formed. Pour into greased cake pan, and bake for 35 minutes, or until a toothpick inserted into the center comes out clean.
Let cake cool completely before moving on to the next step.
In a large bowl, crumble the cake with your hands until fine. Set aside.
For the buttercream: In the bowl of a stand mixer fitted with a beater attachment, beat the butter on medium speed for 2 minutes, until creamy. Scrape down the edges with a spatula and add the cocoa powder and vanilla. Beat on medium/slow until incorporated, about 1 minute.
Add 1 cup of the confectioners’ sugar and 3 teaspoons of milk, beat on high for 2 minutes, scrape down the sides and repeat with remaining cup of confectioners’ sugar and 3 tsp milk, beat on high for 2 more minutes.
Scrape all of the buttercream into the bowl of cake crumbs and stir with a spatula until completely combined.
Line a baking sheet with parchment paper and set aside.
Using a cookie scoop or a spoon, scoop out balls of dough, about the size of a golf ball, roll into a ball with your hands and place on the cookie sheet.
Refrigerate the cake pop balls for at least 30 minutes before continuing to the next step.
In the meantime, get a double broiler ready, with your choice of candy melts or chocolate.
After your cake pops have rested in the fridge for 30 minutes, melt your chocolate coating in the double broiler.
Tip: To get your cake pops to adhere to the sticks, use a small amount of the melted coating. Dip the cake pop stick directly into the melted coating, and then into the cake pop. Let set for a few minutes before moving on.
Now you can either transfer the chocolate coating to a thin tall container, or just dip your cake pops directly into the double broiler. I prefer to put some of the melted chocolate into a small bowl and use a spoon to scoop the melted chocolate over the cake pops. Very gently tap the cake pop sticks against the edge of the bowl and transfer to cake pop stand to dry. Top with sprinkles if desired.
Let the cake pops set in the fridge overnight before serving.