Heat oven to 350 degrees. Spread macadamia nuts on a baking sheet, and bake until golden, about 10 minutes. Set baking sheet on a wire rack to cool.
Line an 11-by-18-inch baking pan with parchment paper. Using a food processor or rolling pin, finely crush graham crackers. Place in a medium bowl. Stir in melted butter. Press mixture into the bottom of prepared baking pan in an even layer. Sprinkle the chocolate over the graham crackers. Sprinkle the coconut over the chocolate. Sprinkle the reserved nuts over the coconut.
Using a microwave or double boiler, heat the caramel until liquid. Drizzle caramel over macadamia nuts. Bake until golden, about 20 minutes. Transfer pan to a wire rack to cool. Cut into 3/4-by-1 1/4-inch pieces.