Preheat your oven to 350°F (175°C). Line a muffin tin with cupcake liners to make removing the cupcakes easier once they are baked.
In a large mixing bowl, whisk together the all-purpose flour, cocoa powder, baking soda, baking powder, and salt. This will create a uniform base for your cupcakes.
In another bowl, beat together the softened butter and sugar until light and fluffy. This should take about 2-3 minutes.
Add the egg and 2 teaspoons of vanilla extract to the butter and sugar mixture. Mix until well combined.
Slowly add in the milk, canola oil, and hot brewed coffee to the mixture. Stir until everything is thoroughly combined and smooth.
Gradually add the dry ingredients to the wet mixture, stirring gently until just combined. Be careful not to overmix; a few lumps are perfectly fine.
Pour the batter into the prepared muffin tin, filling each liner about 2/3 full. Bake in the preheated oven for 18-20 minutes or until a toothpick inserted in the center comes out clean.
In a mixing bowl, beat together the softened butter and packed brown sugar until creamy. Add in the heavy cream, powdered sugar, scraped vanilla bean seeds, and 2 teaspoons of vanilla extract. Beat until fluffy and well combined.
In a small saucepan, melt the 4 tablespoons of butter over medium heat. Stir in the kosher salt and brown sugar until melted and combined. Add the air-popped popcorn to the pan and toss to coat evenly with the butter mixture. Let it cool for a few minutes, then set aside.
Once the cupcakes have cooled completely, use a piping bag to swirl the vanilla bean buttercream frosting on top of each cupcake. Generously top with the sugared popcorn, pressing down slightly to help it adhere.
Melt the chocolate chips in a microwave-safe bowl until smooth. Drizzle the melted chocolate over the cupcakes for an elegant finish.