Baking cakes: Preheat oven in 350 degree F/180 degree C
In a bowl add all purpose flour,baking powder and salt mix well.
In a mixing bowl whisk butter and sugar until fluffy then add egg(one at a time)whisk for 2 minutes,then add milk and vanilla extract mix well. Add dry ingredients on it. Incorporate all ingredients nicely.
Line up cupcake liners on muffin tray pour cake batter 1/2 full and bake for 12 to 15 minutes or toothpick inserted came out clean.
Cool cupcakes completely before frosting.
For making frosting: In medium bowl,mix powdered sugar and butter with spoon or electric mixer on low speed.Stir in vanilla and 1 tbsp of the milk.
If frosting is too thick,beat in more milk, a few drops at a time.
Decorating the cup cakes: Take half frosting in a separate bowl and add red color on it. Mix well and transfer to a pastry bag fitted with a star nozzle tip.
Smear white vanilla frosting on the top of cup cakes. Line four small marshmallows on the bottom edges of cupcakes. Then pipe small red stars giving a triangular shapes of a hat. Then at the top add one more marshmallow. Santa Hat cupcakes is ready to roll.