In a mixing bowl, combine together the melted butter, chopped pecans, and brown sugar.
Pour the mixture into the bottom of a 9-inch cake pan and spread it out evenly so the whole pan is covered. The mixture will be thick, so it will take a few minutes to spread out the mixture evenly.
Open the can of cinnamon rolls and arrange them on top of the butter/pecan mixture.
Bake for 25-30 minutes or until the cinnamon rolls are golden brown.
Allow them to cool for just a couple of minutes. Then place a plate on top of the cake pan and carefully invert the pan over to remove the cinnamon buns out of the cake pan.
In a microwave-safe bowl, mix the icing that comes with the cinnamon rolls with the powdered sugar, heavy cream, and vanilla. Drizzle on top of the pecan cinnamon rolls and serve!
Notes
Turn the pecan rolls out onto a plate a couple of minutes after coming out of the oven so they don't stick!