Butter an 8- or 9-inch square baking dish and line with parchment paper. Stir the Blue Cornbread with Pineapple mix, 1 cup buttermilk, 2 eggs and 4 tablespoons melted butter in a large bowl until just combined. Pour into the prepared dish and bake at 425 degrees until a toothpick inserted in the middle comes out clean, about 25 minutes. Cool, then slice into squares.