Melt the butter in a medium saucepan over medium-low heat. Add apples, thyme, rosemary, and sauté until the apples are slightly tender, about 5 minutes.
Add the piloncillo and cook until the piloncillo starts to caramelize, about 5 minutes. Remove from the heat. Pick out the thyme and rosemary and discard.
Let the apples cool.
Heat an outdoor grill to 500 degrees F. or a stovetop grill panover medium-low heat.
Meanwhile, slice the wheel of brie in half horizontally so you have two circles of cheese. Put the apples on the cut side of one circle, then top with the other circle, cut side down.
Brush the grill grates with the olive oil. Transfer the wheel of brie to the grill and cook about 3 minutes on each side, or until grill marks appear on the cheese rind. Transfer to a platter and serve immediately with a crostini slices or your favorite crackers.
Feel free to use pears or peaches instead of apples. You will need to reduce the cooking time depending on the ripeness of your fruit. Cut the slices a bit thicker than you would with apples as peaches and pears are softer.
Nutrition facts do not include crostini or crackers.