Grease a bundt pan really well with 4 tbsp of softened butter (to ensure the cake comes out of the pan easily when you flip it over). Also, sprinkle a little flour over the pan. This is important because it creates a barrier that keeps the fat from melting directly into the batter when introduced to a hot oven.

In a large measuring cup or bowl melt 1 stick of butter. Then add in 1 & ½ cups of the roughly chopped pecans (save the remaining pecans for later), dark corn syrup, and ½ cup brown sugar. Mix that together until combined. Then pour the syrup pecan mixture evenly into the greased bundt pan.

In another bowl add the yellow cake mix, eggs, water, and vegetable oil. Whisk or beat with a hand mixer until fully combined. Evenly pour half of the cake batter over the syrup pecan mixture in the bundt pan. Set aside the other half of the cake batter.

In a small bowl, add the remaining roughly chopped pecans, cinnamon, and a ¼ cup brown sugar. Mix that up with a fork. Sprinkle this sugar pecan mixture evenly over the cake batter in the bundt pan (you can use as much or as little of the sugar pecan mixture as you'd like).

Then evenly pour the other half over the cake batter over the sugar pecan mixture in the bundt pan.

Bake in the oven at 350°F for about 40 minutes. Let it cool for only 10 minutes.

Then put a large plate or cutting board on top of the pan, and carefully flip it upside down so the cake comes out of the pan onto the cutting board. Enjoy!