In a large pot of cold water, bring the potatoes and garlic to a boil. Salt the water and cook until the potatoes are tender, about 20 to 30 minutes.
Meanwhile in a small skillet melt 1 tablespoon of butter on medium heat and cook shallots until until they begin to brown evenly, then turn heat down to low and continue to cook until very soft, about 10 minutes. Remove from heat and set aside.
Drain the potatoes, return the potatoes to the pot and mash over low heat, or mash in the bowl of stand mixer fitted with the paddle attachment. Add the rosemary, thyme, onion powder, garlic powder, salt, pepper, remaining 4 tablespoons of butter and heavy cream.
Add the cooked shallots and goat cheese crumbles. Fold into mashed potatoes until evenly distributed.
Serve the potatoes warm, topped with additional 2 tablespoons butter.