I just made a peanut butter version of the well dressed cake's swiss meringue buttercream. I left out one ounce of butter and instead added 1/4 cup of peanut butter. Now my icing is too liquidy. Is there anyway to save this?

You could add some powdered sugar into it. It won't be SMBC anymore but it will help firm it up.

I make peanut butter IMBC all the time, but I just add a little into the icing after I've made it. It does soften it up, but it still works fine.

Pretty sure I just added too much peanut butter so I'll know for next time. I ended up added powdered sugar, I like the taste of that icing better anyways It's for my brother so I'm sure he'll like it either way

You need to make a regular batch of SMBC and add the very end when it has come together, add the PB. You will add about 1/4 cup of the PB. It's always perfect texture for me.

By regular batch of SMBC, how many egg whites are we talking?
If I make it with 5 eggs whites and add 1/4 cup of peanut butter it is going to be much different than if I added 10 egg whites.

I'm just trying to get a handle on what is considered a regular size batch of SMBC.

How many egg whites do you use to the 1/4 cup of peanut butter?

Thanks.

I used 5 egg whites, one cup of sugar, 11oz of butter, 1/4 cup of peanut butter. I don't know if this failed because I added the peanut butter at the wrong time or if it was just too much peanut butter. I'm going to try another time, slowly adding PB at the very end

My recipe is 5 egg whites, 1 cup sugar, 12 ounces of butter. Once it comes together I add about 2/3 cup peanut butter. I've never had any problem with it being too runny.