Start by preheating your oven to 350°F (175°C). While it’s heating up, line a standard 12-cup muffin pan with paper liners.
In a bowl, whisk together your all-purpose flour, cornstarch, and baking powder.
Beat the granulated sugar and softened salted butter together in a separate mixing bowl. Mix on low at first, then go high and cream it for 3 to 4 minutes, until it’s soft, airy, and pale
Add the eggs one at a time, mixing until each one disappears into the batter. Then stir in your vanilla extract, it brings that cozy, classic cupcake aroma we all love.
Now, gently mix things together in parts: a bit of the flour mix, then the milk, more flour, the buttermilk, then finish with the rest of the flour. Don’t overmix, just stir until it all looks smooth and combined.
Scoop the batter into the lined muffin cups, filling each about ⅔ full. No need to be exact, just aim for even.
Bake in your preheated oven for 19 minutes. They’re finished baking when a toothpick in the middle pulls out without any batter.
Let them sit in the pan for 5 minutes, then gently move them to a wire rack to cool completely.
Now, for the frosting, in a clean bowl, beat the unsalted butter until soft and smooth. Add the powdered sugar a bit at a time, then pour in the heavy cream, vanilla, and a pinch of salt to round it all out. Beat the frosting until it’s light, airy, and ready to swirl.
Once your cupcakes are cool, go ahead and frost them however you like. Enjoy!