Preheat oven to 350 degrees. Line a 9x13" pan with aluminum foil, leaving an inch or two hanging off of all sides. Spray with PAM.
In a double boiler, melt the butter and chocolate. Stir in the white and brown sugars; add the eggs and vanilla, and stir until the batter is smooth. In a small bowl, combine the espresso and water - stir into the brownie mixture. Add the flour and salt, stir well, and pour onto the foil, spreading evenly. Bake about 30 minutes (do not overbake, as they should be slightly most inside). Cool completely.
Bake the pecans on a cookie sheet for about 8 minutes (you can do this while the brownies are baking as well).
Combine the whipping cream, brown suguar, butter, and Karo in a saucepan. Stir over low to medium heat until smooth. Bring to a slow boil; boil without stirring for 6 minutes. Remove the mixture and let cool - about 5 to 7 minutes. Atir in vanilla and pecans. Remove them from the pan (with the foil) and place flat on countertop or cutting board. Cut into small squares, as they are decadent!