Toast hazelnuts in a 400-degree oven for 5 minutes. Put them in a tea towel and rub them against each other to remove skins. Chop and set aside. Raise oven temperature to 500 degrees F.
Combine honey and Scotch whiskey in a small sauce pan and bring to a boil, stirring. Turn off heat.
Meanwhile, cut off stems of figs then cut in half, lengthwise. Spray an gratin dish large enough to hold all the figs in one layer with butter-flavor spray. Put in figs, cut side up. Drizzle with honey-Scotch mixture. Sprinkle with hazelnuts.
Bake 7 to 10 minutes, depending on size, or just until they soften but are not falling apart. Cool to warm and put 4 to 6 fig halves on each of 4 serving plates. Spoon pan juices over figs. If desired, put a mint sprig in the middle.