Pre heat the oven to 350 degrees.
Place the brie on a rimmed baking sheet lined with parchment paper. With a sharp paring knife cut out the rind from the top leaving a 1" edge around the side of the brie. Scoop out a small amount of the cheese to create an indentation. See photo.
In a small bowl, mix together the KahlĂșa, nuts, butter & sugar until well combined. Spoon the nut mixture on top of the brie making certain it is mounded within the center of the cheese. Sprinkle with a few flakes of smoked sea salt.
Bake for 15 minutes at 350 degrees until the nut mixture is bubbly and the interior of the brie is soft and runny. Let rest for 3-5 minutes then with two large spatualas carefully transfer to a serving platter. Serve with tart apple wedges or fancy ginger snaps.