Preheat the oven to 350 degrees F (175 degrees C). Grease a 9x13-inch baking pan.
Stir cake mix, vanilla pudding mix, and butterscotch pudding mix together in a medium bowl. Add eggs, oil, and water; mix until well blended.
Stir brown sugar, cinnamon, and nuts together in a separate bowl. Pour half of the batter into the pan, spread evenly. Sprinkle with half of the nut mixture. Cover with remaining batter and sprinkle with remaining nut mixture.
Bake in the preheated oven for 20 minutes, then turn the oven down to 325 degrees F (165 degrees C) and bake until a toothpick inserted into the center comes out clean, an additional 35 to 40 minutes.
