Preheat your oven to 350°F (175°C). Line two muffin tins with paper liners to prevent the cupcakes from sticking.

In a small bowl, whisk together 1 ½ cups of flour, 1 teaspoon of baking soda, and ½ teaspoon of salt. Set this aside for later.

In a large mixing bowl or the bowl of an electric mixer, beat ½ cup of softened butter and 1 cup of brown sugar together until light and fluffy. This usually takes about 2-3 minutes.

Add 2 eggs, one at a time, to the butter mixture, making sure each egg is fully mixed in before adding the next. Then, add 1 teaspoon of vanilla extract and 4 ounces of melted unsweetened chocolate. Stir until everything is smooth.

Slowly add the dry ingredients (flour mixture) to the butter mixture, alternating with 1/2 cup of sour cream. Mix gently until just combined. Finally, fold in 1/2 cup of hot coffee (or water) until the batter is smooth.

Fill each cupcake liner about 3/4 full with the batter. Bake in the preheated oven for 12-15 minutes, or until a toothpick inserted into the center of a cupcake comes out clean.

In a mixing bowl, combine ½ cup of softened butter, ⅓ cup of cocoa powder, and 2 cups of powdered sugar. Mix on low until the ingredients are combined.

Stir in 3-4 tablespoons of heavy cream, 2 tablespoons of fudge topping, and 1 teaspoon of vanilla extract. Whip the frosting on high speed until it's fluffy and easy to spread.

Once the cupcakes are fully cooled, spread the frosting on top and enjoy your delicious homemade treats!