1. In a 2- to 3-quart pan over low heat, frequently stir butter, unsweetened chocolate, and Mexican chocolate until melted and smooth. Remove from heat and stir in brown sugar, eggs, cinnamon, vanilla, flour, and pine nuts until well blended.
2. Spread batter evenly in a buttered and floured 8-inch square baking pan.
3. Bake in a 350° oven until edges feel firm to touch and begin to turn a shade darker, 25 to 30 minutes.
4. Run a knife between pan rim and brownie. Let cool in pan on a rack, about 1 hour. Cut into 9 or 16 squares.
Note: Nutritional analysis is per small brownie.