Preheat the oven to 350 ℉ (180 ℃) and line a cupcake form with parchment paper.
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
Cream the butter with the sugar on medium high speed for 3-4 minutes or until light and fluffy.
Mix in the vanilla and eggs, one at the time on medium speed until combined.
In a small bowl, mix together the warm water, sour cream, and oil until smooth.
Scrape down the sides of the mixing bowl and alternate between adding the dry ingredients and the wet ingredients (1/2 of the dry first, then 1/2 of the wet and so on). Gently folding or mixing on low speed inbetween each addition. Careful not to overmix.
Pour the batter into the lined cupcake forms about halfway full. Bake for 15-18 minutes or until a wooden skewer comes out clean (crumbs are fine). For jumbo cupcakes bake for 3-5 extra minutes.
Allow the cupcakes to cool completely before filling and frosting.