Combine brown sugar, granulated sugar, syrup, and milk Cook to soft ball stage (234Â°).
Cool 10 minutes.
Add vanilla and beat by hand about 2 minutes.
Add pecans and beat until mixture loses its gloss.
Drop by heaping tablespoons on a single thickness of buttered aluminum foil or 3 layers of buttered waxed paper.
(If necessary, add a teaspoon or so of hot water to keep candy at right stage for forming into patties.)