Preheat the oven at 160ºC/320ºF conventional oven and line a 12-cup cupcake tray with 12 cupcake liners.
In a large mixing bowl, add granulated sugar, cake flour, baking powder, baking soda and salt and mix it together so everything has been combined.
210 g cake flour, ½ teaspoon baking soda, ½ teaspoon baking powder, ½ teaspoon salt, 200 g granulated sugar
Then add the butter and with a hand mixer or in a stand mixer, using the paddle attachment, mix it together until the butter has coated the dry ingredients and it looks sandy and crumbly.
80 g butter
In another mixing bowl add the sour cream, eggs, vegetable oil and vanilla extract and with a hand whisk mix it all together until combined.
240 g sour cream 14-18%, 2 large eggs, 1 tablespoon vegetable oil, 1 ½ teaspoon vanilla extract
Pour the wet ingredients into the dry and with the electric mixer mix it all together until smooth. Make sure there are no lumps left in the batter.
Divide the cupcake batter into the 12 cupcake liners and bake them for 22-23 minutes. Let the cupcakes cool in the hot pan. After 5 minutes, gently remove the cupcakes from the cupcake pan and let them cool down completely on a wire rack.