Preheat oven to 350°F. Line 24 muffin cups with cupcake papers. Set aside.

In a small bowl, combine the flours. Set aside.

In a large bowl, cream the butter with an electric mixer until smooth. Add the sugar gradually and beat until fluffy, about 3 minutes. Add the eggs, 1 at a time, beating well after each addition.

Add the dry ingredients in 3 parts, alternating with the milk and vanilla. With each addition, beat until the ingredients are incorporated but do not over beat. Using a rubber spatula, scrape down the batter in the bowl to make sure the ingredients are well blended.

Divide the batter between the cupcake liners, filling them about 3/4 full. Bake for 20 to 25 minutes, or until a cake tester inserted into the center of the cupcake comes out clean. 

Cool the cupcakes in the pans for 15 minutes before transferring to a wire rack to cool completely.

Place the butter in a large mixing bowl. Add 4 cups of the sugar and then the milk and vanilla. Beat with an electric mixer on medium speed until smooth and creamy, about 3 to 5 minutes. Gradually add the remaining sugar, 1 cup at a time, beating well after each addition (about 2 minutes), until the icing is thick enough to be of good spreading consistency. You may not need to add all of the sugar. If desired, add a few drops of food coloring and mix thoroughly.

Frost each cupcake and top with sprinkles, if desired