In a skillet over medium heat, melt 2 tablespoons of butter. Add 2 cups of chopped pecans and toast for about 5 minutes, stirring frequently until golden. Set aside to cool.

In a large saucepan, melt 2 sticks of butter over medium-high heat. Add 1 cup of granulated sugar and 1 cup of packed brown sugar. Stir until combined, about 2-3 minutes.

Pour in 1-1/8 cups of heavy whipping cream, 1/4 teaspoon of salt, and 1 tablespoon of vanilla extract. Stir until well-mixed and creamy, about 1-2 minutes.

Bring the mixture to a rolling boil and stir occasionally for 4 minutes to prevent sticking. After 4 minutes, remove from heat.

Gradually stir in 4 cups of powdered sugar until nearly smooth. Whisk for another minute to ensure well-blended.

Fold in the toasted pecans until evenly distributed throughout the fudge mixture.

Pour into a parchment-lined baking dish, smoothing the top. Allow to cool for at least 3 hours before cutting.