Add the strawberries to a small saucepan. Heat on medium-low and mash the strawberries as you cook. Continue to cook the strawberries until it is cooked down to about ¼ cup. Allow to cool completely.
Preheat the oven to 350 degrees F. Link baking sheets with cupcake liners - remember this recipe makes 14 cupcakes.
Add the freeze-dried strawberries to a food processor or blender and process until it is a fine powder.
Add the flour, baking powder, baking soda salt, and strawberry powder together and stir well. Set aside.
Add the butter, cooled strawberry puree and sugar together. Beat well until well-combined.
Add the eggs and vanilla to the butter mixture and beat well for about 4 minutes.
Mix together the buttermilk and sour cream in a small bowl.
Add ⅓ of the flour mixture to the butter mixture and stir until just combined. Add in half the buttermilk mixture and stir until just combined. Add half the remaining flour, then the remaining buttermilk and stir until just combined. Add the remaining flour and mix until just combined.
Fill the cupcake liners ⅔ full, then bake the cupcakes for 16 - 18 minutes, or until a toothpick comes out clean.
Allow to cool, and while they are cooling, make the frosting.
Process the freeze-dried strawberries until they are a powder set aside.
Beat the butter until smooth. Add the powdered sugar one cup at a time, the mixture may seem crumbly, this is normal. Beat int he salt, and a tablespoon of heavy cream.
Separate half the frosting mixture.
In one half, mix in the freeze-dried strawberries. Add more heavy cream as needed.
In the other half, add the Nutella, and heavy cream as needed.
Fill a piping bag with the strawberry frosting and Nutella frosting.
Pipe onto the cooled cupcakes.
Notes
To quickly cool the strawberry puree I spread it thinly on a plate and put it in the freezer. You can make cake flour by Replacing 1 tablespoon of flour with one tablespoon of cornstarch per cup of flour needed. Make sure you sift the flour and cornstarch. If you forget to take out your butter, you can use this post to learn how to soften butter quickly.