Swiss meringue/7-Minute frosting is light, fluffy, and sweet without being cloying. It also suited my purposes - I wanted something that would be sweet enough to help balance out the tart flavor of the curd without overwhelming it. Because a very specific shade of blue was requested and I didn't want to take any chances with that, I used water instead of juice and vanilla bean-scented sugar instead of vanilla extract in the frosting I made for the wedding cake and cupcakes. With only the vanilla to flavor it, the frosting is like a high grade of marshmallow fluff - smooth, shiny, and melting on the tongue. With the juice to flavor it, there is an additional layer of fragrance and flavor to dance on the tastebuds. Both are delicious! Best used the same day it is made; can be put into pastry bags [piping bags] and refrigerated for a day or two with minimal deflating. If there are leftovers, you can use them to make a pavlova: spread a layer about 1" [2.5 cm] thick on parchment paper and bake on a cookie sheet at 250 °F [120 ℃ or Gas Mark ½] for about 1 ½ hours. Turn off oven and let cool. Serve topped with lilikoi curd, whipped cream, and assorted chopped fresh fruit (I like pineapple and berries).
Lilikoi Frosting (adapted from classic 7-minute frosting - there are many recipes out there; I printed out Paula Deen's recipe from the Food Network website, used the same proportions, but changed up the instructions to be based on temperature and appearance).
One batch will frost a 9" 4-layer cake or 24 cupcakes.
2 large egg whites
1 ½ cups [165 g] granulated white sugar [UK: caster sugar works better as it will dissolve faster. US: if desired, first measure and then grind the sugar finer in a blender or food processor]
1 Tbs corn syrup [or 1/4 tsp / 1 g cream of tartar - if not available, you can leave this out; the frosting will then be less stable and should be served as soon as possible]
1/3 cup [80 mL] fresh lilikoi (passionfruit) juice (or lemon juice, or water)
pinch of salt
1 Tbs [15 mL] vanilla extract
With electric hand-held mixer, beat egg whites on low for 1 minute. Beat in remaining ingredients. In a bain-marie or double boiler, beat on high until temperature reads 140 °F [60 ℃], then continue to beat on high for 7 - 8 minutes until soft peaks will stand on the surface. Remove from heat and continue beating on low for 2 minutes. Should be fluffy, smooth, and glossy. If it begins to separate after cooling (water visible in bottom of bowl under the fluff), it is undercooked and can be re-beaten over hot water to get it completely cooked.
Update (August 2019): for those looking for a lilikoi glaze, it’s super easy:
Lilikoi Drizzle or Glaze
2 cups [8 oz or 226 g] confectioners sugar (also called icing sugar and powdered sugar - fine sugar with cornstarch)
2 - 4 Tablespoons [about 30 - 70 ml] fresh lilikoi (passionfruit) juice
Stir the lilikoi juice into the sugar a spoonful at a time, until it’s the consistency you want. For a drizzle that will sit on top of a cake, use 2 Tablespoons of juice. For a glaze that soaks into the cake, use more. I test it on a corner of a cake to see how thick or thin it is. The total amount will depend on things like how humid it is in the room you are working in and how warm the cake is. If you want the drizzle to stand up and hold its shape, make sure the cake is completely cool first!
While reading A Homemade Life, one of the recipes that I immediately bookmarked was the Vanilla Bean Buttermilk Cake. I had been asked to do a cake and a cupcake tower for a wedding, and the requested flavor: liliko'i! (that's passionfruit for those of you not familiar with the Hawaiian name). By the time I was reading A Homemade Life, I'd already read through several recipes for liliko'i cakes, all of which called for starting with a box mix and juice concentrate and I was hoping to find a way to bring in more liliko'i flavor.
The primary request: make them delicious. Make the cupcakes pack a big flavor punch - something to get people to stop for a moment and be wowed. With that in mind, I started thinking about using a liliko'i filling, and chose to modify the Vanilla Bake Shop's Meyer Lemon Curd recipe. There is a version of the Vanilla Bean Buttermilk Cake recipe on Orangette, Molly Wizenberg's blog. It's not exactly the same as the book version, with one difference being that the online version uses a combination of baking soda and baking powder, and the book version calls for 1 Tablespoon of baking powder. That seemed like a LOT of baking powder to me, but I went ahead and used it, and the cake turned out just fine. Because I'm currently living in a house with an old and cranky oven, I am doing all my cake recipe testing over at Mom & Dads, and they have been happy to be my tasters. When I pulled the cake out of the oven, I already knew that this was not going to be the cake recipe for the wedding, and slicing and tasting confirmed it. While I tried to get specific about why (the best I could come up with initially was "it's good cake, just not wedding cake") I kept eating it, and then I speared a chunk with my fork, swept it through the puddle of lilikoi curd on my plate, popped it into my mouth, and found that with the lilikoi curd on it, I don't care. WOW. This is good curd. Back to the specifics of why it won't be wedding cake - in the book, Molly does say it is best on the day it is made, and I agree, having sampled the cake the day after and then the day after that. I'm planning to make the layers ahead of time and freeze them, so I need something that will hold up better in storage. Mine wound up with several big air bubbles in it (and based on photos I've seen online, this is pretty common). Those can be dealt with either by taking the pan of batter and giving it a couple of good firm whacks on the kitchen counter (risking splattering cake batter all over the place) or by sweeping a thin-bladed knife or a skewer back and forth through the batter in the pan, before putting it in the oven.
Modifications: because I didn't have a vanilla bean, I used only vanilla extract and I suspect that it just didn't pack the same punch. If I make this again, I'll be sure to use the vanilla bean. I still don't have parchment paper, and I think I've got a springform pan but I couldn't find it, so I buttered and floured a regular cake pan generously. The cake didn't stick and turned out of the pan easily; however, I suspect it wound up being a little denser as a result, because the cake couldn't climb up the sides of the pan as easily as it might have with just butter. I didn't do the Glazed Oranges that are paired with this cake recipe since I was making the lilikoi curd.
The lilikoi butter has a wonderful flavor, fruity and floral at the beginning with a nice tangy finish. It's sweet without being cloying. The texture is surprisingly light and the mouthfeel is actually a bit fluffy, which some people like a lot (I'm not as big a fan of this, but that didn't stop me from eating several spoonfuls). This is also not the recipe that will wind up in the wedding - it is too runny for what I have in mind, although it does firm up some after refrigeration. I will be making it again, though. If you try it, do keep in mind that this makes a big batch, and the recipe says it will keep for 3 - 4 days in the fridge.
Vanilla Bake Shop's Meyer Lemon Curd (via Martha Stewart)
Modifications: replaced the lemon juice with fresh liliko'i juice (cut open several lilikoi and press the pulp in a fine mesh sieve, discarding the seeds. Alternately, if you have access to a Vitamix, blend the pulp until the seeds are ground into fine specks - they are edible and contribute to the flavor nicely). I did use lemon zest but I think this could be left out. The recipe calls for putting it through a fine mesh sieve; I didn't and the texture didn't seem to suffer at all.