Line two baking sheets with parchment paper, wax paper or aluminum foil.
In a heavy bottom pot over medium-high heat bring sugar, brown sugar, salt and milk to a boil, then cook until it reaches 230°F; about 8 minutes. Stir occasionally after it boils.
Add butter, vanilla and pecans, cook until mixture has thickened reaches 240°F; about 5-6 minutes. You want to stir it continuously for the first 2 minutes. When the candy is close to being finished, as you stir you will be able to see the bottom of the pot.
Then very quickly scoop out pralines. Just move very fast because the pralines will harden fast. Let cool for 5-10 minutes before eating.
