Ultimate Double Chocolate Cookies

* 12 ounce(s) Semi-Sweet Chocolate Chips
* 11 1/2 ounce(s) 60% Cacao Bittersweet Chocolate Chips
* 6 tablespoon(s) unsalted butter
* 3 eggs
* 1 cup(s) sugar
* 1/3 cup(s) all-purpose flour
* 1/2 teaspoon(s) baking powder
* 1 cup(s) chopped walnuts

1. In double boiler over hot water, melt bittersweet chocolate chips and butter. In large bowl with electric mixer or whisk, beat eggs and sugar until thick; stir into chocolate mixture. In small bowl, stir together flour and baking powder; stir into chocolate mixture. Gently mix in semi-sweet chocolate chips and walnuts.

2. Using a sheet of plastic wrap, form dough into two logs, each 2 inches in diameter and about 12 inches long. As dough will be quite soft, use plastic wrap to hold dough in log shape. Wrap tightly; refrigerate at least 1 hour or until firm. (Dough may be frozen; thaw in refrigerator before proceeding with recipe.) Heat oven to 375°F. Unwrap dough; with sharp knife, cut into 3/4-inch slices. Place slices 1 1/2 inches apart on greased or parchment-lined cookie sheet.

3. Bake 12 to 14 minutes or until shiny crust forms on top but interior is still soft. Cool on baking sheet; store in airtight tin up to 1 week.