Preheat oven to 350 and grease a bundt pan generously with solid vegetable shortening then dust with flour or granulated sugar or coat with Wilton cake release. Set aside.
In the bowl of your electric mixer, add cake mix, vanilla pudding, sugars, and cinnamon. Stir to combine.
Add eggs, water, oil, and buttermilk and mix well.
Pour into prepared pan.
Bake for 45 to 5 minutes or until a wooden pick inserted in center comes out clean or with dry crumbs.
Remove the cake from the oven and set aside while making the sauce.
BUTTER GLAZE
Add butter, sugar, and water to a sauce pan.
Cook over medium heat whisking constantly until boiling. Continue to stir and boil for 1 minute or until sugar is no longer grainy. Remove the pan from the heat and stir in the vanilla.
Pour mixture over warm cake and let set before inverting the cake onto a serving plate
This cake is great served warm with vanilla ice cream. Store in an airtight container in the refrigerator for 5 days.