Ingredients
1¼cupsall-purpose flour,spoon and leveled
2tspbaking powder
¼tspsalt
6tbspunsalted butter,softened to room temperature
¾cupgranulated sugar
3large egg whites,room temperature
1tsppure vanilla extract
6tbspfull-fat sour cream,room temperature
3tbspinstant espresso coffee powder
2tbsphot water
6tbspwhole milk,room temperature
1cupunsalted butter,softened to room temperature
4cupsconfectioners’ sugar
¾cupNutella
⅓cupheavy cream or whole milk
1tsppure vanilla extract
pinchsalt
chocolate sprinkles and raspberries,optional
Preparation
Preheat the oven to 350 degrees F. Line a 12-cup muffin pan with cupcake liners. Line a second pan with 2 liners; set aside.
Whisk the flour, baking powder, and salt together. Set aside.
Using a handheld or stand mixer fitted with a paddle attachment, beat the butter on high speed for about 1 minute until smooth and creamy. Add the granulated sugar and beat on high speed for about 2 minutes until creamed together. Scrape down the sides and up the bottom of the bowl with a rubber spatula as needed.
Add the egg whites and vanilla extract. Beat on high speed until combined, then beat in the sour cream. Scrape down the sides and up the bottom of the bowl as needed so everything is incorporated.
Stir the espresso powder and hot water together until smooth, then stir this into the milk. Set aside for a second.
With the mixer running at low speed, add the dry ingredients until just incorporated. With the mixer still running on low, slowly pour in the espresso/milk mixture until combined; do not overmix. Whisk it all by hand to make sure there are no lumps at the bottom of the bowl; the batter will be on the thin side.
Pour/spoon the batter into the liners – fill only halfway with the batter to avoid spilling over the sides. Bake for about 18 to 20 minutes, or until a toothpick inserted in the center comes out clean. Allow cooling completely before frosting.
In a large bowl using a handheld or stand mixer fitted with a paddle attachment, beat the butter on medium speed for about 2 minutes until smooth. Stop the mixer and add confectioners’ sugar, Nutella, heavy cream, and vanilla extract. Beat on low speed for about 30 seconds, then increase to medium-high speed and beat for 2 full minutes.
Add up to ½ cup of confectioners’ sugar if frosting is too thin or 1 tablespoon of cream if frosting is too thick. Add a pinch of salt if the frosting is too sweet.
Frost and decorate cooled cupcakes using a Wilton 1M tip or #12 round tip.
Serve immediately. Store leftover cupcakes in the refrigerator for up to 5 days.
