Strawberry Cupcakes

These are the ever-popular Sprinkles cupcakes, and you can find the recipe anywhere on the interwebs, so I have no qualms about reposting it here. The cake is perfect: dense, not fluffy, and not very sweet. The frosting is too sweet on its own, but on the cupcakes, it's ideal. Pro tip: you really have to beat the crap out of the butter and make sure it's super-fluffy before adding the wet ingredients; then, when you add the berry puree, beat again, on high, for several minutes. If it looks like it's all congealed and nasty, be patient. It /will/ come together.

For cupcakes:

1. I pureed a cup of washed strawberries, then set it aside. I put out the milk, eggs, and butter to get to room temperature.
2. I turned the oven to 350 and put liners in my muffin pan.
3. I whisked together 1 1/2 C flour, 1 t baking powder, and 1/4 t salt. In a liquid measuring cup, I put 1/4 C whole milk, 1 t vanilla, and 1/3 C of the berry puree (or maybe a bit more).
4. With a stand mixer, I creamed 1 stick of unsalted butter for a LONG time until very fluffy. Then I added 1 C sugar and beat again until very fluffy. I turned the speed to medium and slowly added 1 whole egg and 2 egg whites, one at a time, stopping to scrape the bowl a few times.
5. With the mixer on low, I added 1/2 the flour mixture. When it was incorporated, I added the milk. Same drill with the rest of the flour. 
6. I divided the batter into my muffin cups, and baked for 25 minutes on the dot.

For frosting:

1.  I creamed 2 sticks of cold butter with a pinch of salt until very light and fluffy. Then I slowly added 1 1/2 C of confectioner's sugar.
2. Then I /very slowly/ added in 1 t of vanilla and about 1/4 C of the berry puree. Then I added a bit more berries, and a bit more, until it tasted super strawberry-ish. I kept the mixer running until it was all incorporated and airy, but it isn't light like a buttercream frosting.
3. Then I frosted the cooled cupcakes and ate about 5 of them.