Line baking sheets with parchment paper.
Combine sugars and cream in a heavy saucepan over medium heat. Stir until sugars dissolve.
Add butter and salt; cook until mixture reaches soft-ball stage (235–240°F) using a candy thermometer.
Remove from heat. Stir in pecans and vanilla. Beat vigorously for 2–3 minutes until mixture thickens slightly and turns opaque.
Use a metal spoon. Drop spoonfuls onto prepared sheet. Let cool until firm.
For perfectly coated pralines, place the cooled candies in a large metal bowl with powdered sugar or pecan dust. Proceed to toss the candies gently for 2-3 minutes.
