Line a baking sheet with parchment paper and set aside.
Add the cubed butter to a medium saucepan and melt over medium heat.
Add the granulated sugar and brown sugar, then stir to combine.
Pour in the heavy cream and continue stirring until the mixture is smooth.
Cook over medium heat, stirring occasionally, until the mixture comes to a gentle boil.
Continue cooking until the caramel mixture thickens and reaches approximately 234–238°F (112–114°C).
Remove the saucepan from the heat.
Add the baking soda, salt, and vanilla extract, then stir until well combined.
Add the pecan halves and gently fold them into the caramel mixture until evenly coated.
Allow the mixture to cool slightly until it thickens.
Scoop small portions of the pecan mixture onto the prepared parchment-lined baking sheet.
Let the pralines cool completely until firm and set.
Carefully remove the pralines from the parchment paper, then serve and enjoy.
