Preheat your oven to 350°F (175°C) and line a muffin pan with cupcake liners.

In a medium bowl, whisk together the flour, baking powder, and salt.

In a large mixing bowl, beat the softened butter and sugar together until light and fluffy, about 3-4 minutes.

Add the eggs, one at a time, and mix in the vanilla extract until fully combined.

Gradually add the flour mixture alternating with milk, mixing until just combined.

Spoon the batter into the lined muffin pan, filling each liner about two-thirds full. Bake for 18-20 minutes until a toothpick comes out clean.

Let the cupcakes cool in the pan for 5 minutes, then transfer them to a wire rack to cool completely.

Prepare the chocolate buttercream and pipe onto completely cooled cupcakes.