Combine first 3 ingredients in a heavy saucepan; cook, stirring often, over low heat until chocolate melts.
Remove from heat; cool slightly.
Beat eggs and sugar at medium speed with an electric mixer until smooth; add chocolate mixture, beating well.
Combine flour, baking powder, and salt; add to chocolate mixture, stirring just until dry ingredients are moistened. Fold in chocolate morsels, pecans, and walnuts.
Drop batter by tablespoonfuls 2 inches apart onto lightly greased baking sheets.
Bake at 325 for 12 to 15 minutes or until done. Cool cookies on baking sheet 1 minute.