Here's a tried-and-true recipe for white cupcakes.
Preheat the oven to 350 degrees and line your cupcake tin with paper or foil liners. Cream the butter and sugar together. Add the eggs, one at a time, beating well after each addition. Stir in the vanilla extract. Sift together the dry ingredients and add to the butter mixture one third at a time, alternating with the milk. Pour into the prepared cupcake pan and bake for 18 to 24 minutes, or until an inserted toothpick comes out clean. Makes 12 cupcakes.