Peanut Butter Chocolate Brownie

花生醬巧克力焦烤蛋糕
Category: Dessert
Style: Western
Difficulty: Easy
Portion: Makes 1 8-inch square cake

Ingredients
Batter:
8 tbsp unsalted butter, cut into small pieces, plus more for pan
2 oz dark chocolate, coarsely chopped
4 oz semisweet chocolate, coarsely chopped
2/3 cup all purpose flour
1/2 tsp baking powder
1/4 tsp salt
1/2 cup sugar
3 large eggs
2 tsp vanilla extract
Filling:
4 tbsp unsalted butter, melted
1/2 cup sugar
3/4 cup smooth peanut butter
1/4 tsp salt
1/2 tsp vanilla extract

Procedures
Preheat oven to 325F. Line a buttered 8-inch square baking pan with foil or parchment paper, allowing 2 inches to hang over sides. Set pan aside.
Make batter:
Put butter and chocolates in a heatproof medium bowl. Microwave on high until melted in 20 seconds intervals. Stir between each microwave sessions. Let cool slightly.
Whisk together flour, baking powder, and salt in a separate bowl, and set aside.
Whisk sugar into chocolate mixture. Add eggs, and whisk until mixture is smooth. Stir in vanilla. Add flour mixture; stir until well incorporated.
Make filling:
Stir together butter, sugar, peanut butter, salt, and vanilla in a bowl until smooth.
Assemble
Pour half of batter into prepared pan, and spread evenly with a rubber spatula. Place dollops of filling about 1 inch apart on top of batter. Drizzle remaining batter on top, and gently spread to fill pan. Place dollops of remaining filling on top.
With a butter knife, gently swirl filling into batter, running knife lengthwise and crosswise through layers. Bake until a cake tester inserted into brownies comes out with a few crumbs but is not wet, about 45 minutes. Let cool slightly in pan, about 15 minutes. Lift out brownies; let cool completely on a wire rack before cutting into squares.