Preheat the oven to 350°F and grease a 9x13-inch baking dish with non-stick spray.

In a large mixing bowl, combine the yellow cake mix, buttermilk, 4 ounces of cream cheese, and eggs. Beat until the batter is smooth and fully combined.

Pour the batter into the prepared baking dish and spread evenly. Bake for 28 to 30 minutes, or until a toothpick inserted in the center comes out clean.

Let the cake cool slightly before proceeding.

Toast the chopped pecans in a dry skillet over medium-high heat for 4 to 5 minutes until fragrant and lightly browned. Remove from heat and let cool.

In a microwave-safe bowl, combine 8 ounces of softened cream cheese and ½ cup of softened butter. Melt in short bursts and stir until smooth. Add the vanilla extract and milk, mixing until combined.

Gradually whisk in the powdered sugar to avoid lumps, creating a smooth glaze.

Poke holes evenly across the surface of the slightly warm cake using the handle of a wooden spoon or a large straw.

Slowly pour the warm glaze over the cake, ensuring it fills all the holes. Immediately sprinkle toasted pecans on top.

Refrigerate the cake for at least 1 hour and 30 minutes before slicing to allow the glaze to set and soak into the cake.