Make the Brownie Cupcakes: Preheat your oven to 350°F (175°C) and line a 12-cup muffin tin with cupcake liners.
Prepare the Wet Ingredients: In a large mixing bowl, whisk together 1/2 cup of melted butter and 1 cup of granulated sugar until smooth and well combined. Add the 2 eggs and 1 teaspoon of vanilla extract, mixing well until the mixture is thick and creamy.
Sift and Mix the Dry Ingredients: Sift in 1/3 cup of unsweetened cocoa powder, 1/2 cup of all-purpose flour, 1/4 teaspoon of salt, and 1/4 teaspoon of baking powder. Stir the dry ingredients into the wet ingredients just until combined. Be careful not to overmix, as this can affect the texture of the cupcakes.
Fold in the Chocolate: Gently fold in 1/2 cup of semi-sweet chocolate chips and 1/4 cup of dark chocolate chunks. These will melt into the batter while baking, creating pockets of gooey chocolate throughout the cupcakes.
Fill the Cupcake Liners: Divide the batter evenly into the cupcake liners, filling each about 2/3 full. Tap the pan gently on the counter to release any air bubbles.
Bake the Cupcakes: Bake for 18–20 minutes, or until a toothpick inserted into the center comes out with moist crumbs (not wet batter). Let the cupcakes cool completely in the pan on a wire rack before frosting.
Make the Chocolate Frosting: While the cupcakes are cooling, make the frosting. In a large bowl, beat 1/2 cup of softened unsalted butter until creamy. Add 1 1/2 cups of powdered sugar, 1/4 cup of cocoa powder, 1 teaspoon of vanilla extract, and a pinch of salt. Mix on low speed until combined, then add 2 tablespoons of heavy cream or milk and beat on high until smooth and fluffy. If you want a thicker frosting, add more powdered sugar; for a creamier frosting, add more milk or cream.
Frost the Cupcakes: Once the cupcakes are completely cool, pipe or spread the chocolate frosting onto each cupcake. Swirl the frosting for a professional finish, or go for a rustic look with a smooth spread.
Decorate: Top the cupcakes with mini chocolate chips, chocolate shavings, or a drizzle of fudge for an extra indulgent touch.
Serve: Enjoy your Triple Chocolate Brownie Cupcakes immediately or store them in an airtight container at room temperature for up to 3 days. These cupcakes are sure to satisfy even the most intense chocolate cravings!
