Preheat the oven to 350°F (175°C). Then, line a muffin pan with cupcake liners or lightly grease it.

In a large bowl, beat the softened butter and sugar until light and fluffy.

Next, add the vanilla extract and eggs, one at a time. Beat well after each addition.

In another bowl, mix the all-purpose flour, baking powder, and salt until well combined.

Gradually add the dry ingredients and buttermilk to the butter mixture, alternating between them. Mix gently until just combined.

Next, spoon the batter into the prepared cupcake liners, filling each about two-thirds full.

Bake for 20–25 minutes or until a toothpick inserted into the center comes out clean. Then, transfer the cupcakes to a cooling rack and let them cool completely.

In a bowl, combine the instant vanilla pudding mix and cold milk. Whisk until thick and creamy, then refrigerate until ready to use.

Place the dark chocolate chips in a heatproof bowl. Heat the heavy cream in the microwave for about 1 minute, until hot but not boiling, then pour it over the chocolate.

Let the chocolate sit briefly, then stir until smooth. Add the light corn syrup and let the ganache rest for 2–3 minutes to thicken slightly.

Once cooled, carefully cut the cupcakes in half. Alternatively, cut a small hole in the center of each cupcake and remove some cake to make room for the filling.

Next, spoon the vanilla pudding onto the bottom half or into the center of each cupcake. Then, gently replace the cupcake tops.

Lastly, slowly drizzle the chocolate ganache over each cupcake. Let it settle slightly, then serve and enjoy!