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

In a bowl, whisk together the all-purpose flour, baking powder, and salt. Set aside.

In a large mixing bowl, beat the unsalted butter and sugar with an electric mixer on medium speed for about 2-3 minutes until light and fluffy.

Mix in the vegetable oil, vanilla extract, and eggs one at a time. Beat until thoroughly combined.

Gradually add the dry ingredient mixture to the butter mixture, alternating with the milk. Start and end with the flour mixture. Mix until combined, but do not overmix.

Spoon the batter into the prepared cupcake liners, filling them about two-thirds full.

Bake for 18-20 minutes or until a toothpick inserted in the center comes out clean. Allow the cupcakes to cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.

In a bowl, beat the unsalted butter on medium speed until creamy.

Gradually add the powdered sugar, mixing well. Incorporate the vanilla extract and a pinch of salt.

Add water or milk one tablespoon at a time until the frosting is smooth and spreadable.

Once the cupcakes are fully cooled, spread or pipe the frosting on top using a spatula or piping bag.