• 1

  In a heatproof bowl set over (but not touching) barely simmering water in a pan, stir ¼ cup butter and bittersweet chocolate often until mixture is melted and smooth.

• 2

  In a large bowl, with a mixer on high speed, beat sugar, eggs, and vanilla until smooth.

• 3

  Add chocolate mixture and beat until well blended.

• 4

  Stir in flour and baking powder, then beat just until moistened.

• 5

  Stir in macadamia nuts, chocolate chips, and coconut.

• 6

  Drop dough in 1-Tablespoon portions about 2 inches apart on buttered 12×15-inch baking sheets.

• 7

  Bake clusters in a 350°F regular or convection oven just until firm on the edges but still soft when pressed in the middle, 8 to 10 minutes; if baking two sheets at once in one oven, switch their positions halfway through baking.

• 8

  Let clusters cool on sheets for 5 minutes, then use a wide spatula to transfer to racks to cool completely.

Notes

• !

  Take care not to overbake them; their centers should remain soft and chewy.