Peanut butter cups always remind me what a good match peanut butter and milk chocolate are. Here a hefty dose of peanut butter flavors the cupcake batter and milk chocolate the glaze for this cupcake version of the popular combination.
Make the cupcakes. Position a rack in the middle of the oven. Preheat the oven to 350°F. Line 12 muffin tin cups with paper cupcake liners.
Sift the flour, baking powder, and salt into a medium bowl and set aside.
In a large bowl, using an electric mixer on medium speed, beat the butter, peanut butter, and brown sugar until smoothly blended and lightened in color, about 1 minute. Stop the mixer and scrape the sides of the bowl as needed during mixing. Mix in the egg. Add the vanilla and beat for 1 minute, or until the batter is smooth. On low speed, add the flour mixture in 3 additions and the milk in 2 additions, beginning and ending with the flour mixture and mixing just until the flour is incorporated and the batter looks smooth.
Fill each paper liner with a generous 1/4 cup of batter, to about 1/3 inch below the top of the liner. Bake just until the tops feel firm and are lightly browned and a toothpick inserted in the center comes out clean, about 22 minutes. There will be a few small cracks on top. Cool the cupcakes for 10 minutes in the pan on a wire rack.
Carefully place the wire rack on top of the cupcakes in their pan. Protecting your hands with pot holders and holding the pan and rack together, invert them to release the cupcakes onto the wire rack. Turn the cupcakes top side up to cool completely.
Make the glaze. In a medium saucepan, heat the cream and butter over low heat until the cream is hot and the butter has melted. The mixture should form tiny bubbles and measure about 175°F on a thermometer; do not let it boil. Remove the pan from the heat, add the milk chocolate, and let it sit in the hot cream for about 30 seconds to soften. Add the vanilla and whisk the glaze until it is smooth and all of the chocolate has melted. (Return the glaze to low heat if necessary to melt the chocolate completely, whisking constantly.) The glaze should be thick enough to hold its shape when spread over the cupcakes. If it is too liquid to spread, let it sit at room temperature for 5 to 15 minutes, depending on the temperature of your kitchen.
Using a small spatula, spread 1 tablespoon of the glaze over the top of each cupcake.
The cupcakes can be covered and stored at room temperature for up to 3 days.
MAKES 12 REGULAR CUPCAKES
CUPCAKE MAKING : 20 minutes
CUPCAKE BAKING : 350°F, for about 22 minutes
1 cup unbleached all-purpose flour
1 teaspoon baking powder
1/4 teaspoon salt
6 tablespoons (3/4 stick) unsalted butter, at room temperature
3/4 cup smooth peanut butter, at room temperature
1 cup packed dark brown sugar
1 large egg
1 teaspoon vanilla extract
1/2 cup milk (any fat content)
1/4 cup heavy whipping cream
1 tablespoon unsalted butter
1 cup (about 53/4 ounces) chopped milk chocolate or milk chocolate chips
1/2 teaspoon vanilla extract