Pour the chilled heavy whipping cream into a large mixing bowl. Beat with an electric mixer on medium-high speed until soft peaks form. This should take about 2-3 minutes. Set aside in the fridge to keep cold.

In another bowl, mix the peanut butter and powdered sugar together. Add 1 tablespoon of milk or heavy cream at a time, stirring after each addition, until the mixture becomes smooth and spreadable.

Gently fold half of the whipped cream into the peanut butter mixture. Use a spatula and fold slowly to keep the mousse light and airy.

Once incorporated, fold in the remaining whipped cream until no streaks remain. Stop folding as soon as the mixture looks uniform to avoid deflating it.

Divide the mousse evenly into four 6 ounce cups or serving glasses. Smooth the tops with the back of a spoon, or use a piping bag with a star tip for a different presentation.

Cover each serving with plastic wrap and refrigerate for at least 2 hours to allow the mousse to set properly.

Before serving, decorate each mousse with your choice of toppings like shaved chocolate, chocolate chips, roasted peanuts, a dollop of whipped cream, or crumbled Nutter Butter cookies.

Serve chilled and enjoy!