Vanilla Buttermilk Cupcakes with Strawberry Buttercream Frosting

I'm going to make these for a couple of my neighbors today. I have the NICEST neighbors- always taking my Kate to school and helping me out in lots of different ways, and these cupcakes are so delicious that after they eat them, they will be indebted to ME. And that's how I like it.

Vanilla Buttermilk Cupcakes

1 1/2 cups flour
1 1/4 teaspoon baking powder
1/4 teaspoon baking soda
1/4 teaspoon salt (leave this out if you use salted butter. Which I do, because salted is all I keep on hand.)
1 1/2 sticks unsalted butter, softened
1 cup sugar
2 large eggs
1 egg yolk
1 1/2 teaspoons vanilla
1/2 cup buttermilk

1. Preheat oven to 350 degrees. Fit muffin tins with about 18 liners. Whisk together flour, powder, soda, and salt.

2. Beat butter and sugar until fluffy. One by one, mix in eggs, egg yolk, and vanilla. Add the flour mixture alternately with the buttermilk, mixing until smooth.

3. Spoon out butter into muffin liners- fill about half full: these should puff up a lot.

4. Bake for about 20 minutes. Cool and top with your favorite frosting.

Strawberry Buttercream Frosting
I'm forever in the debt of my bonus sister Amber for procuring this recipe from a popular bakery in the town she used to live in. The secret to a good, creamy buttercream is to mix it for a long time. I hate it when I can taste the individual powdered sugar grains in my frosting. So let your mixer run until your frosting is smooth and creamy. You may have to keep tasting it, but someone's got to make the sacrifice.

1/2 cup softened butter
1 lb. powdered sugar
1 tsp vanilla
1/2 pound strawberries, fresh or frozen, pureed in the food processor or blender. (If you are a Fancy Nancy, run the puree through a strainer to remove the seeds.)

Mix together the butter, sugar, and vanilla. It will look kind of lumpy. With the mixer running, add the strawberry puree until frosting is the correct consistency. I wish I could help you out with the exact measurement, but it varies every time. If you have leftover puree, put it on pancakes or french toast.