Here is my recipe that I entered last year in a local experimental ale contest. It won BOS and People's Choice. It was scaled up by the local brewery to a 15BBL system. Needless to say that the recipe is not cost prohibitive when scaling up from 10 gallons to 15BBL!

They decided to add 20lbs of toasted coconut to the whirlpool and finish off the beer with coconut extract. The final product lacked little coconut flavor and aroma, but was a great coffee beer! I took 5 gallons of the wort home and treated it with the toasted coconut and other ingredients in the secondary. It was way better than the extract commercial version. The recipe calls for a lot of coconut, but I think it is needed to overcome the dominant coffee, chocolate and roast flavors. I sampled the beer every day or 2 and then pulled the ingredients one by one when I was satisfied with the flavors.
Hawaiian Porter
A ProMash Recipe Report
BJCP Style and Style Guidelines
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12-B Porter, Robust Porter
Min OG: 1.048 Max OG: 1.065
Min IBU: 25 Max IBU: 60
Min Clr: 22 Max Clr: 42 Color in SRM, Lovibond
Recipe Specifics
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Batch Size (Gal): 10.25 Wort Size (Gal): 10.25
Total Grain (Lbs): 27.16
Anticipated OG: 1.065 Plato: 15.89
Anticipated SRM: 42.3
Anticipated IBU: 37.0
Brewhouse Efficiency: 70 %
Wort Boil Time: 60 Minutes
Pre-Boil Amounts
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Evaporation Rate: 15.00 Percent Per Hour
Pre-Boil Wort Size: 12.06 Gal
Pre-Boil Gravity: 1.055 SG 13.62 Plato
Formulas Used
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Brewhouse Efficiency and Predicted Gravity based on Method #1, Potential Used.
Final Gravity Calculation Based on Points.
Hard Value of Sucrose applied. Value for recipe: 46.2100 ppppg
Yield Type used in Gravity Prediction: Fine Grind Dry Basis.
Color Formula Used: Morey
Hop IBU Formula Used: Rager
Additional Utilization Used For Plug Hops: 2 %
Additional Utilization Used For Pellet Hops: 10 %
Grain/Extract/Sugar
% Amount Name Origin Potential SRM
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69.0 18.75 lbs. Pale Malt(2-row) America 1.036 2
11.8 3.21 lbs. Munich Malt(2-row) America 1.035 6
8.7 2.36 lbs. Crystal 60L America 1.034 60
3.9 1.06 lbs. Carafa Germany 1.030 500
6.5 1.77 lbs. Chocolate Malt America 1.029 350
Potential represented as SG per pound per gallon.
Hops
Amount Name Form Alpha IBU Boil Time
-----------------------------------------------------------------------------
1.08 oz. Galena Pellet 13.00 31.3 60 min.
1.00 oz. Willamette Pellet 5.00 5.7 30 min.
Extras
Amount Name Type Time
--------------------------------------------------------------------------
16.00 Oz Coconut, Flaked Other 7 Days(fermenter)
32.00 Oz Coconut, Flaked Other 14 Days(fermenter)
2.00 Unit(s)Vanilla Bean Spice 4 Days(fermenter)
12.00 Oz Cacao Nibs Other 7 Days(fermenter)
1.50 Oz Kona Coffee Coffee 4 Days(fermenter)
1.50 Oz Molokai Coffee Coffee 4 Days(fermenter)
Yeast
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White Labs WLP001 California Ale
Water Profile
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Profile: Lincoln, NE
Profile known for: Moderate hardness/alkalinity
Calcium(Ca): 61.0 ppm
Magnesium(Mg): 15.0 ppm
Sodium(Na): 35.0 ppm
Sulfate(SO4): 84.0 ppm
Chloride(Cl): 20.0 ppm
biCarbonate(HCO3): 190.0 ppm
pH: 8.00
Mash Schedule
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Mash Type: Single Step
Grain Lbs: 27.16
Water Qts: 36.13 - Before Additional Infusions
Water Gal: 9.03 - Before Additional Infusions
Qts Water Per Lbs Grain: 1.33 - Before Additional Infusions
Saccharification Rest Temp : 154 Time: 0
Mash-out Rest Temp : 0 Time: 0
Sparge Temp : 0 Time: 0
Total Mash Volume Gal: 11.21 - Dough-In Infusion Only
All temperature measurements are degrees Fahrenheit.
Notes
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Flaked coconut & cacao nibs toasted in oven @ 350F x 15-20min, then added to secondary
Molokai and Kona coffee french press blend 24oz added to secondary
Dry hop coconut, cacao nibs, vanilla, and kona/molokai coffee to secondary
Hoser