1/2 cup butter 4 (1-oz.) unsweetened chocolate baking squares, chopped 3 cups semisweet chocolate morsels, divided 1 1/2 cups all-purpose flour 1/2 teaspoon baking powder 1/2 teaspoon salt 4 large eggs 1 1/2 cups sugar 2 teaspoons vanilla extract 2 cups chopped pecans, toasted

Combine butter, unsweetened chocolate, and 1 1/2 cups chocolate morsels in a large heavy saucepan. Cook over low heat, stirring constantly, until butter and chocolate melt; cool.
2. Combine flour, baking powder, and salt; set aside.
3. Beat eggs, sugar, and vanilla at medium speed with an electric mixer. Gradually add flour mixture to egg mixture, beating well. Add chocolate mixture; beat well. Stir in remaining 1 1/2 cups chocolate morsels and pecans.
4. Drop dough by 2 tablespoonfuls 1 inch apart onto parchment paper-lined baking sheets.
5. Bake at 350° for 10 minutes. Cool slightly on baking sheets; remove to wire racks to cool completely.