Pre-heat oven to 350° and spray a 6 cup bundt pan with non-stick spray - set aside
In a microwave safe bowl melt 6 Tablespoons of butter, then add the 6 Tablespoons of brown sugar and heat in microwave again until sugar is melted and them mixture is bubbling. My microwave took about 1 minute and 30 seconds give or take for the butter and sugar to bubble. You can also do this on the stove top.
Pour the butter and sugar mixture into the bottom of your greased bundt pan, sprinkle chopped walnuts evenly around the pan over the butter/sugar.
Stand your cinnamon rolls up in your bundt pan - all 16 spread out around the pan evenly.
Bake in your pre-heated oven until cinnamon rolls are done - approximately 25-28 minutes.
Allow to cool for 3-5 minutes once out of the oven, then invert onto a plate to serve. You may have to use a rubber spatala to remove the nuts and caramel from the bottom of the bundt pan!