To make Mary Berry vanilla cupcakes, you will need flour, sugar, baking powder, salt, unsalted butter, eggs, whole milk, and vanilla extract. Preheat your oven to 350°F and line your cupcake tin with cupcake liners. In a mixing bowl, cream the butter and sugar together until light and fluffy. Gradually add the beaten eggs, followed by the flour, baking powder, salt, whole milk, and vanilla extract. Mix until well combined and spoon the batter into the cupcake liners. Bake for 20-25 minutes until golden brown and springy to the touch. Once cooled, decorate with your frosting of choice or dust with powdered sugar.