In a skillet, melt the butter over medium heat. Add the thinly sliced onion, a pinch of salt, and cook until the onions are soft and golden brown, about 10-15 minutes. Stir in the brown sugar and dried thyme, and continue cooking for another 5 minutes until caramelized. Set aside to cool.
In a mixing bowl, combine the goat cheese and cream cheese. Using a rubber spatula, mix until smooth and well combined.
Once the caramelized onions have cooled, fold them into the cheese mixture. Add salt and black pepper to taste, and mix well to ensure an even distribution of flavors.
Cover the bowl with plastic wrap and refrigerate the mixture for at least 30 minutes. This will firm it up and make it easier to roll into truffles.
While the cheese mixture is chilling, chop the almonds finely and place them on a plate. On another plate, spread the chopped parsley.
Once the cheese mixture has chilled, use a small scoop or your hands to form bite-sized balls. Roll each truffle first in the chopped almonds, then in the parsley, coating them evenly.
Place the truffles on a serving platter. These Caramelized Onion Goat Cheese Truffles can be served immediately or stored in the refrigerator until serving. Enjoy with your favorite crackers or fresh bread!