My old home-brew store had a Karmeliet clone extract with grains recipe. I never made it myself but I thought I'd share for comment. Personally I think there may be a bit too much wheat in this recipe (I'd probably just use 8 oz.) and I'd stick to continental hops for this (like a Nobel hop + Styrian Goldings). If this would be more to style I'd do what I could to sweat the details to get a drier beer to result. Something with a F.G. below 1.015. I'd make a yeast starter and would probably switch to a Wyeast 3787 Trappist High Gravity Yeast. But I'd try to dial it in a bit more to get the 8.4% ABV the beer is supposed to have. I think I'd try to pitch like at 65 degrees F and ferment it from there up to 68 degrees.
Belgian (Karmeliet) Tripel
makes 5 gallons
3.3 lbs Light Malt Syrup
3.3 lbs Wheat Malt Syrup
1 lb Light Dry Malt Powder
1 lb Candi Sugar (boil 15 mins)
1 lb Belgian Pilsner Malt
½ lb Wheat Malt
½ lb Aromatic Malt
¾ lb Flaked Oats
1 oz Sweet Orange Peel (boil 15 mins)
½ oz Coriander (crushed, boil 15 mins)
½ oz Northern Brewer hops (boil 60 mins)
½ oz US Golding Hops (finishing hops, boil last 5 mins)
½ tsp Irish Moss (boil 45 min)
¾ cup corn sugar for bottling
White Labs WLP 550 Belgian Ale Yeast
1 Servomyces tablet (for optimal fermentation, boil 15 min)
original gravity 1.081
final gravity 1.019
alcohol content 8.2%
IBU: 22
Steep crushed malted grain in 2 gallons of 150° water for 30 minutes. Remove the grain from the hot water with a strainer, then bring water to a boil. When boiling starts, remove pot from burner and add 1 cup malt syrup. Return to a boil, then add boiling hops and boil for 60 minutes. Add Irish Moss for last 45 minutes of boil. Add Candi Sugar, Sweet Orange Peel, Coriander, and Servomyces (optional) for the last 15 minutes of the boil. Add finishing hops for last 5 minutes of the boil. Then add remainder of malt syrup and dry malt extract and stir to mix, wait 10 minutes to sanitize. Fill your sanitized carboy with 2 gallons of cold water. Strain the hot wort into the carboy and top off to the 5.5 gallon mark. Add yeast when beer is less than 78°, and ferment and bottle as usual.