Cook the Mixture

1. Combine Ingredients: In a medium saucepan, combine the granulated sugar, brown sugar, heavy cream, and butter.
2. Cook Over Medium Heat: Stir the mixture constantly until it comes to a boil.
3. Boil for 5 Minutes: Allow the mixture to boil without stirring until it reaches a soft-ball stage (about 234°F to 240°F, or 112°C to 115°C). This should take around 5 minutes.

Add the Pecans

1. Remove from Heat: Take the saucepan off the heat and stir in the vanilla extract and chopped pecans.
2. Cool Slightly: Let the mixture cool for a few minutes until it thickens slightly.

Form the Pralines

1. Drop Spoonfuls: Using a spoon or cookie scoop, drop spoonfuls of the mixture onto a parchment-lined baking sheet.
2. Let Set: Allow the pralines to cool completely and set for about 10 minutes.