01 - Line a baking sheet with parchment paper or a silicone baking mat, ensuring a non-stick surface for the pralines.
02 - In a heavy-bottomed saucepan, combine the granulated sugar, light brown sugar, whole milk, unsalted butter, and fine sea salt. Place over medium heat and stir continuously until the butter is fully melted and the mixture comes to a full boil.
03 - Attach a candy thermometer to the side of the pan, ensuring it does not touch the bottom. Continue to boil, stirring frequently to prevent scorching, until the mixture reaches precisely 238°F (soft-ball stage). This process typically takes 8 to 10 minutes.
04 - Immediately remove the saucepan from the heat. Promptly stir in the pure vanilla extract and pecan halves. Continue stirring for 2 to 3 minutes; the mixture will begin to thicken and become creamy, yet it should remain pourable.
05 - Working swiftly, use a spoon to drop individual portions of the praline mixture onto the prepared baking sheet, leaving ample space between each. Allow the pralines to cool completely at room temperature until they are fully set and firm, approximately 20 to 30 minutes.
06 - Once completely set, store the pecan pralines in an airtight container at room temperature. They will maintain their freshness for up to one week.