Heat the butter, peanut butter, and 1 pint of heavy cream over medium heat until the peanut butter and butter melt.

Remove from heat and allow to cool slightly.

Whisk powder into the liquid 1/4 cup at a time.

Make sure the powder is completely dissolved.

(Blend for a few seconds if necessary.) Refrigerate mixture to cool completely.

While mixture is cooling, beat the remaining heavy cream and vanilla until stiff peaks form.

Do not over-beat.

Fold the mixtures together, make sure to combine well.

You may need to whisk the refrigerated mixture before folding into the whipped cream, to make sure that none of the protein powdered settled.

Pour into containers and freeze for at least 6 hours, or overnight