1. Heat oven to 375 degrees F. Sift together flour, cocoa, baking powder and salt.
2. Beat butter in large bowl until smooth and creamy. Beat in brown and granulated sugars until light and fluffy. Beat in eggs, 1 at a time. Beat in vanilla.
3. On low speed, beat flour mixture into butter mixture. Stir in hot coffee. Fold in M&Ms and chopped nuts.
4. Drop by heaping tablespoonfuls onto ungreased baking sheets.
5. Bake in 375 degrees F oven for 8 to 11 minutes or until set. Let cool slightly on baking pan. Transfer cookies to wire rack to cool completely.