I made the brown sugar cubes from dark brown sugar and my teaspoon measuring spoon. I tapped them out onto a baking sheet and let the sugar dry for 2 - 3 days in a cold oven. Once dry, they can be bagged in a zip top bag or snap lid container.
I used the following ingredients:
Hamiltons Islay Blended Scotch Whisky
Bulleit Bourbon
Grand Imperial Orange Liqueur