Coconut Swirl Brownies (too good to pass up!)

Coconut Swirl Brownies
from Martha Stewart's Cookies

Makes 9 large or 16 small

1/2 cup unsalted butter, cut into small pieces
3/7 cup plus 1 tablespoon sugar
1/3 cup sweetened condensed milk
2/3 cup unsweetened shredded coconut
1 large egg white
2 1/4 teaspoons vanilla
2 ounces unsweetened chocolate, coarsely chopped
4 ounces semisweet chocolate, coarsely chopped
2/3 cup all-purpose flour
1/2 teaspoon baking powder
1/4 teaspoon coarse salt
3 large eggs

Preheat oven to 350F. Line a buttered 8-inch square baking pan with parchment, allowing a 2-inch overhang. Butter lining (not overhang).

Stir together 1 tablespoon of sugar, the condensed milk, coconut, egg white, and 1/4 teaspoon of the vanilla in a bowl.

Put butter and both chocolates in a heatproof bowl set over a pan of simmering water; stir until melted. Let cool slightly.

Whisk together flour, baking powder, and salt in a bowl.

Whisk remaining 3/4 cup sugar into chocolate mixture. Add eggs; whisk until mixture is smooth. Stir in remaining 2 teaspoons vanilla. Add flour mixture; stir until well combined.

Pour one-third of the chocolate batter into the prepared pan. Spread evenly with an offset spatula. Drop dollops of the coconut mixture (about 1 tablespoon each) on top of batter, spacing about 1 inch apart. Drizzle remaining batter on top, and gently spread to fill pan. Drop dollops of remaining coconut mixture on top.

Gently swirl coconut mixture into batter with a butter knife, running the knife lengthwise and crosswise through layers. Bake until a cake tester inserted into the middle of the brownies comes out with a few crumbs, but is not wet, 35 to 40 minutes. Let cool slightly in pan, about 15 minutes. Lift out; let cool completely on a wire rack before cutting into squares.