Line a baking sheet with foil and set aside.

In big saucepan, combine the pecans, sugar, butter, brown sugar, milk and vanilla, all over a medium heat. Heat that stuff to between 234 and 240 F. It's ready if you can drop a small amount of syrup into some cold water and it forms a soft ball that flattens when you take it out.

Drop spoonfuls of the mix onto the prepped baking sheet and let them cool and flatten completely.