Chocolate Peanut Butter Layer Brownies

Preheat oven to 350 degrees F. Butter and flour a 9" square baking pan, knocking out excess flour.

In a double boiler, melt unsweetened chocolate, stirring until smooth. Remove from heat and let cool to room temperature.

In a large bowl with an electric mixer, beat butter and sugar until light and fluffy. Beat in eggs, 1 at a time, beating well after each addition. Add vanilla.

In a small bowl, sift together flour, baking powder and salt. Beat into butter mixture just until blended.

Divide batter between 2 bowls. Whisk peanut butter into batter in 1 bowl. Whisk melted chocolate into batter in other bowl. Add chopped bittersweet or chips to it.

Spread peanut butter batter evenly in the pan. Drop chocolate batter by large spoonfuls onto peanut butter batter and spread carefully to form an even layer.

Bake brownies in middle of oven for 35 to 40 minutes or until a tester comes out with crumbs attached. Cool brownies completely in pan on a wire rack before cutting into squares.

Brownies keep layered between sheets of wax paper in an airtight container at cool room temperature for 5 days.