St. Patrick's Day Cupcakes with White Chocolate and Pistachios

Preparation

1. Make the cupcakes:

   Step 1

   Position racks in top and bottom thirds of oven; preheat to 350°F. Line 2 standard 12-cup muffin tins with liners. Whisk flour, baking powder, and salt in a medium bowl. Stir milk and vanilla in a small bowl or measuring cup.

   Step 2

   Cream sugar and butter in the bowl of a stand mixer fitted with the paddle attachment at medium speed, scraping down sides, until pale and fluffy, 3–4 minutes. Add eggs one at a time, beating to blend after each addition.

   Step 3

   Reduce mixer speed to low and beat in dry ingredients in 3 additions, alternating with milk mixture in 2 additions, beginning and ending with dry ingredients. Beat in food coloring until you reach desired green color. Fold in chocolate chips and pistachios.

   Step 4

   Divide batter among muffin cups. Bake cupcakes, rotating baking sheets front to back and top to bottom halfway through, until tops are firm and lightly browned and a tester inserted into the center comes out clean, 13–16 minutes. Transfer pans to wire racks and let cool.

2. Make the buttercream and assemble the cupcakes:

   Step 5

   Lightly whisk egg whites and sugar in a medium bowl set over a saucepan of simmering water until hot to the touch or a candy thermometer registers 140°F.

   Step 6

   Pour hot egg whites mixture into stand mixer bowl and whip with the whisk attachment on medium-high speed until doubled in volume and stiff peaks form. Meanwhile, cut butter into 2" pieces. (The butter should be slightly moist on the outside but cold inside.)

   Step 7

   Fit stand mixer with paddle attachment. Add half of butter to bowl. Pulsate (turn on and off) mixer several times until meringue covers butter completely. Add remaining butter and pulsate mixer several more times. Beat on lowest speed, then slowly increase speed every 10 seconds to medium-high. Continue to beat until mixture begins to look light and fluffy. Stop mixer, scrape bowl, then reduce speed to low. Add vanilla and continue to beat on low speed 45 seconds. Increase speed to medium-high and beat until smooth, 45–60 seconds. Add food coloring and mix until you reach desired color.

   Step 8

   Frost each cupcake with a swirl of buttercream, then dust with gold luster dust, if using. Top with sprinkles, if using.

3. Do Ahead

   Step 9

   Unfrosted cupcakes can be made 3 days ahead; cover tightly and store at room temperature. Frosted cupcakes can be made 3 days ahead; cover tightly and chill.