First, toast the 2 cups pecans. You can do this on the stove over medium-low heat or in the oven at 300° F. Heat them until they are just fragrant and toasty, 5-10 minutes. Be careful not to burn them. Remove them from the heat and set them aside.
Line a baking sheet with parchment or wax paper and set aside.
In a large heavy bottomed saucepan, combine the 1½ cups light brown sugar, 1½ cups granulated sugar, 3 Tablespoons molasses, and 1 cup whole milk. Heat over medium high heat until the sugar dissolves, stirring frequently with a wooden spoon.
Bring to a boil and continue to cook for about 5 minutes. The candy should be at the soft ball stage or read 240° F on a candy thermometer.
Remove the pan from the heat and stir in the 4 Tablespoons butter, pecans, 1 pinch salt and 1 teaspoon vanilla extract. Stir vigorously for about 2-3 more minutes or until the mixture starts to thicken.
Quickly drop heaping Tablespoons full of praline mixture onto the parchment lined baking sheet. Allow them to cool completely then store in an airtight container at room temperature.
Notes
Feel free to be generous with your two cups of pecans and use up to 2.5 cups. The pecans are my favorite part!