1/2 cup butter
1/2 cup flour
1/4 cup cocoa powder
1 tsp salt
2 tsp baking powder
10 oz. semisweet or bittersweet chocolate
6 large eggs
2 cups sugar
2 tsp vanilla extract
1/2 cup sour cream
1 cup chopped walnuts (optional)
1 cup semisweet chocolate chips
1Preheat your oven to 325 degrees. Line a 9x13 pan with heavy duty aluminum foil and spray well with oil or coat with butter.
2Sift the flour, cocoa powder, salt and baking powder together and set aside.
3Melt the butter and the chocolate in a medium bowl over a sauce pan of boiling water. Stir well to combine and remove from heat.
4Place the eggs, sugar and vanilla in the bowl of an electric mixer and fit the mixer with the balloon whip. Whip on high speed for 1-2 minutes or until slightly thickened. Add the melted chocolate mixture and mix on medium speed for 30 seconds. Add the flour mixture and mix on low for 10 seconds, then on medium for 10 seconds. Finally, add the sour cream and mix on medium just to combine, about 5 seconds.
5Stir the nuts if using into the batter by hand with a rubber spatula. Scrape the batter into the prepared pan and smooth the top. Sprinkle evenly with the chocolate chips.
6Bake at 325 degrees for 45-50 minutes or until a toothpick inserted in the middle comes out clean. Let cool in the pan on a rack.
7When cool, turn out onto a cutting board and peel away the foil. Flip back over and cut into bars.
Walnuts are optional in this recipe but certainly add to the texture and flavor. You can also substitute another favorite nut - like pecans - if you prefer.