In a large heavy saucepan, bring to a boil the first five ingredients. Once boiling, cook to the soft ball stage, which takes approximately 20-30 minutes. Remove from heat.
Set pot off burner and allow to cool down to room temperature, not luke warm. It needs to really cool down. You do not want it to be warm so be patient.
Once cool, stir well then mix in vanilla and pecans. Pour into a buttered oblong dish. Now let it harden before cutting. This takes several hours. Depending on the humidity, it can take an entire day and night so be patient.