Makes 9 large or 16 small squares
FOR THE BATTER
* 8 tbls (1 stick) unsalted butter, cut into small pieces, plus more for pan
* 2 ounces good-quality unsweetened chocolate, coarsely chopped
* 4 ounces good-quality semisweet chocolate, coarsely chopped
* 1/3 cup all-purpose flour
* 1/3 cup whole wheat flour
* 1/2 tsp baking powder
* 1/4 tsp fine sea salt
* 5 tbls Truvia or Splenda
* 1/2 cup sugar
* 6 egg whites
* 2 tsp pure vanilla extract
FOR THE FILLING
* 4 tbls unsalted butter, melted
* 1/2 cup confectioners' sugar
* 3/4 cup smooth Almond butter
* 1/4 teaspoon sea salt
* 1/2 teaspoon pure vanilla extract
Directions
1. Preheat oven to 325 degrees. Butter an 8-inch square baking pan and line with parchment, allowing a 2-inch overhang. Butter lining (not overhang).
2. Make batter: Put butter and chocolates in a heatproof medium bowl set over a pan of simmering water; stir until melted. Let cool slightly. Whisk together flours, baking powder, and sea salt in a bowl.
3. Whisk granulated sugar into chocolate mixture. Add egg whites, and whisk until mixture is smooth. Stir in vanilla. Add flour mixture; stir until well combined.
4. Make filling: Stir together butter, confectioners' sugar, almond butter, sea salt, and vanilla in a bowl until smooth.
5. Pour one-third of batter into prepared pan; spread evenly with a rubber spatula. Drop dollops of almond butter filling (about 1 tbls 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 filling on top. Gently swirl almond butter filling into batter with a butter knife, running the knife lengthwise and crosswise through layers.
6. Bake until a cake tester inserted into brownies (avoid center and edges) comes out with a few crumbs but is not wet, about 45 minutes. Let cool slightly in pan, about 15 minutes. Lift out; let cool completely on a wire rack before cutting into squares.
NOTE:To swirl brownies, work quickly so that batter and filling don't set. Use two large spoons to drop dollops of filling on the first layer of batter about one inch apart. Repeat with next layer of batter and remaining filling. Drag a butter knife back and forth through the layers with the tip touching the bottom of the pan.
