In a sauce pan, add the butter, brown sugar and heavy whipping cream.
Bring to a boil and reduce to medium heat for 5 minutes.
Keep stirring during the 5 minutes and allow mixture to thicken.
Add the pecans, stir and remove from heat.
Allow the mix to cool and then pour over your pumpkin bundt cake
Reheat
If you did not pour all the sauce on the cake, you can heat in the microwave in a microwave safe container. Microwave at 30 second intervals to heat. It may boil, so use caution.