Nut butter buttercream?

[jrshaul]

I have a peanut butter swiss meringue buttercream frosting / pie filling recipe that goes like this:

1/2c butter
1/2c creamy unsalted all-peanut PB
3  egg whites
2/3c granulated sugar
1/2c brown sugar. (I use regular sugar for cake frosting.)

Pulverize brown sugar to dust in blendar. Mix warm melted butter with PB and brown sugar; do NOT heat PB or it gets all grainy. Make swiss meringue with egg whites and sugar; fold together. 

It's not bad, and as an improvement on the traditional Cool Whip PB fluff pies, it's a huge improvement. Compared to the Jif-butter-and-powdered-sugar "buttercreams" I've seen...well, it doesn't physically engage my gag reflex. But it's  too heavy for a pie and not quite smooth enough for either application. 

I'd also like to do a pistachio or hazelnut version using whole pistachios and hazelnuts; raw pistachios are cheaper and easier to get as a consumer and they produce an excellent color. I was thinking just blend the pistachios, butter, and sugar in a blender, but I imagine there's a more clever option. 

(Added bonus: Any thoughts on pasteurizing eggs sous vide for meringue? I can't get it to work; they're fine for mayonnaise but won't whip.)

Edited November 4, 2020 by jrshaul (log)

[jrshaul]

I tried the following yesterday. You'll excuse the lack of pictures; the cake was basically inhaled.

- Cook 5 egg whites to 150 sous vide with 310 grams of sugar for one hour.
- Beat until stiff peaks. Or, in my case, you're worried of overheating the kitchenaid mixer.
- Add 4oz room temperature salted butter and 8oz room temperature peanut butter. 

It was good, but stll needs work. Does brown sugar work in meringues? And any advice on sous vide swiss meringues?