- 1-1/4 cups – unsalted butter
- 1 cup – granulated sugar
- 1 cup – firmly packed dark brown sugar
- 3 – large eggs
- 2-1/2 teaspoons – vanilla extract
- 2-1/2 cups – Swans Down Cake Flour
- 1-1/2 teaspoons – baking powder
- 1-1/2 teaspoons – salt
In a medium saucepan, melt butter over medium heat. Cook until butter turns a medium-brown color and has a nutty aroma, about 10 minutes. Remove from heat, and let cool to room temperature.
Preheat oven to 350°. Spray a 13×9-inch baking pan with baking spray with flour, and line bottom of pan with parchment paper.
In a large bowl, stir together brown butter and sugars until combined. Add eggs and vanilla, and beat with a mixer at medium speed until combined.
In a medium bowl, whisk together Swans Down® Cake Flour, baking powder, and salt. Gradually add flour mixture to butter mixture, whisking until combined. Pour batter into prepared pan.
Bake until a wooden pick inserted in center comes out clean, 35 to 40 minutes. Let cool completely on a wire rack.