Triple Threat Chipotle Brownies

Preheat oven to 350 degrees F.

Butter and flour an 8-inch square baking pan. In a heavy 1-quart saucepan, melt bittersweet chocolate, unsweetened chocolate and butter over low heat, stirring until smooth. Remove pan from the heat. Cool mixture to lukewarm and whisk in sugar, vanilla and chipotle paste. Add eggs one at a time, whisking well until mixture is glossy and smooth. Stir in salt and flour until just combined. Stir in chocolate chips. Spread batter evenly in pan and bake in oven 25 to 30 minutes or until a tester comes out with crumbs. Cool brownies completely in a pan on a rack. Cut into squares. Dust with powdered sugar.