Preheat oven to 350°F (175°C). Grease and flour a bundt pan or a 9x13” cake pan. In a large bowl, combine Cake mix, Butterscotch pudding mix, Eggs, Oil, Water (or milk), and Vanilla (if using) Beat with a hand mixer on medium speed for 2–3 minutes, until smooth. Fold in chopped pecans or walnuts if desired.

Pour batter into the prepared pan. Bake for 45–55 minutes (Bundt) or 35–40 minutes (9x13”), until a toothpick comes out clean. Let cool for 10–15 minutes in the pan, then turn out onto a rack and cool completely. Optional: Dust with powdered sugar or drizzle with glaze.

Butterscotch Glaze: Heat brown sugar, butter, and milk in a saucepan over medium heat until it boils. Boil for 1 minute, remove from heat, stir in vanilla. Let cool slightly and drizzle over cooled cake.