½cup(113 g) brown butter, cooled to room temperature
1cup(200 g) granulated sugar
2large eggs, room temperature
1Tablespoonpure vanilla extract
¼cup(56 g) full-fat sour cream (or plain yogurt), room temperature
½cup(120 ml) whole milk, room temperature
Frosting
½cup(113 g) brown butter, cooled to room temperature
½cup(113 g or 1 stick) unsalted butter, room temperature
2 ½cups(300 g) powdered sugar, sifted
2teaspoonspure vanilla extract
Pinchsalt
1-2Tablespoonsmilk
Instructions
Brown the Butter
Place butter pieces in a light-colored pan. Bring to medium heat and stir constantly with a rubber spatula or gently swirl the pan. Keep the butter moving so it melts evenly and doesn’t burn.
The butter will melt, then it will start to foam up. The foam will subside and the butter will start to brown. Once you see little brown flecks and the butter has a nutty aroma, remove it from the heat and immediately transfer to a heatproof bowl.
Let it cool in the bowl before using in cupcake batter and frosting.
Cupcakes
Preheat oven to 350° F. Line a cupcake pan with baking cups.
In a medium bowl, whisk together flour, baking powder, baking soda and salt. Set aside.
In a large mixing bowl, beat ½ cup brown butter and sugar until creamy and light in color, about 2 minutes. Add the eggs one at a time, beating well after each addition. Beat in the vanilla extract and sour cream. Scrape down the sides and bottom of the bowl as necessary.
Gradually add in the flour mixture in three parts, alternating with milk (So it goes flour, milk, flour, milk, flour). Mix until batter is uniform and smooth.
Fill baking cups about three-quarters full and bake for 16 to 18 minutes, or until a toothpick inserted into the center comes out clean. Remove from the oven, transfer cupcakes to a cooling rack, and allow them to cool to room temperature before frosting.
Frosting
In the bowl of a stand mixer (or using a hand mixer), beat ½ cup brown butter with ½ cup unsalted butter until fluffy, about 4 minutes. With the mixer on low speed, gradually add in the powdered sugar until completely incorporated.
With the mixer on medium speed, add the vanilla and salt, and beat for a minute, until fluffy. Add milk until desired consistency is reached.
Transfer to a frosting bag with tip and frost cooled cupcakes.
Notes
Brown butter and immediately remove it from the heat and pan (otherwise it might burn). Read more tips for browning butter here.Store in an airtight container at room temperature for up to 3 or 4 days.Freeze cupcakes after they have cooled completely. Wrap in plastic wrap to prevent freezer burn and then place in an airtight container. Defrost in the refrigerator before bringing to room temperature.