30 January 2009

Butter Cupcakes with Peanut Crunch Buttercream Frosting

White Butter Cake
Adapted from cakelove

12 oz cake flour
3 oz potato starch
1 1/2 tsp baking powder
3/4 tsp salt

3/4 cup egg whites
3/4 cup whole milk
1/4 cup+ 2 tbsp half and half
1 1/2 tsp vanilla extract

1 3/4 sticks unsalted butter, softened
18 oz granulated sugar

Preheat oven to 350. Measure the dry ingredients into a medium bowl. Add the flour, whisking for 10 seconds to blend. Measure the liquid ingredients in a separate bowl, whisking to combine.

In the bowl of a stand mixer fitted with the paddle attachment, cream together butter and sugar on lowest speed for 2-3 minutes. Add the dry ingredient mixture alternating with liquid mixture in 3-5 additions, beginning and ending with dry.

Line cupcake pan with cupcake liners. Fill about halfway. Bake for 25 minutes, until edges are golden and the cake doesn't jiggle in the center. Cool 25-30 minutes, remove from pan to cool completely.

Peanut Crunch Buttercream Frosting
Adapted from cakelove

Yolk Mixture
6 large egg yolks
1/4 cup (2 oz) granulated sugar
3 tbsp potato starch
2 oz (1/2 stick) unsalted butter, softened

Milk Mixture
2 cups whole milk
3 oz (1/2 cup) unsalted roasted peanuts
3/4 cup + 2 tbsp (7 oz) granulated sugar

Flavorings and Butter Mixture
1/4 cup (3 oz) muscovado or dark brown sugar, packed
1 tbsp raw or crystallized honey
1 tbsp natural peanut butter
2 tsps vanilla extract
1 pound (4 sicks) unsalted butter, chilled
1/4 cup granulated sugar

Preheat oven to 350. Combine yolk mixture in a bowl and set aside.

Measure milk mixture ingredients into a 2 qt, saucepan and bring to a boil over medium-high heat. Turn off and let mixture steep for 10 minutes. Strain the peanuts in a fine mesh sieve over a large bowl to capture the flavored milk. Leave the nuts in the sieve to drain, you'll use them later. return the steeped milk to the saucepan and bring to a simmer over medium heat. Slowly pour it into the yolk mixture, whisking slowly until combined. Pour the mixture back into the saucepan. Return the saucepan to stove over medium heat, whisking constantly, but not rapidly, for 4 minutes. The key is to keep the pastry cream moving so it won't scorch on the bottom of the saucepan. When you begin to see large bubbles that burp steam, reduce the heat to the lowest setting and whisk briskly for 1 minute to pasteurize the pastry cream. Pour the pastry cream into the bowl of a standing mixer fitted with the wire whip attachment.

Add the muscovado, honey, peanut butter, and vanilla. Whip on high speed until it's cooled, about 4-5 minutes. Reduce the mixer speed to medium-low and add the butter 1 tbsp at a time. Whip on medium speed until smooth, 2-3 minutes.

Meanwhile, toss the drained peanuts with 1/4 cup sugar in a medium bowl. Place on an ungreased parchment lined cookie sheet and toast for 5-10 minutes, watching closely. Let the peanuts cool completely before breaking them into chunks with your fingers. Add them to the buttercream and mix on low speed until the nuts are full incorporated.