Preheat the oven at 160ºC/ 320ºF conventional oven and line a cupcake tray with 12 cupcake liners.
Sift together the all-purpose flour, baking powder, baking soda and salt and set it aside.
200 g all-purpose, ¼ teaspoon baking powder, ¼ teaspoon salt, ¼ teaspoon baking soda
In a mixing bowl, using the paddle attachment add the butter, smooth peanut butter, and sugar and mix it on high speed for 3 minutes.
50 g butter, 20 g smooth peanut butter, 210 g granulated sugar
Add the eggs one at a time into the mixture and mix it in until combined.
3 eggs
Scrape down the sides of the bowl and continue by adding the flour mixture, continuing on low speed, mixing until just combined.
Finally add the sour cream, vegetable oil and vanilla extract and mix until just combined, make sure not to over mix the cake batter. Using a rubber spatula, give the batter a gentle fold to make sure all of the ingredients have combined.
150 g sour cream 18%, 2 tablespoon vegetable oil, 1 ½ teaspoon vanilla extract
Divide the cake batter into the 12 cupcake liners and bake them for 23-25 minutes or until a cake tester comes out clean.
Let the cakes cool on a cooling rack. After 5 minutes, gently remove the cupcakes from the cupcake tin and let them cool down completely.