Prepare your brownies per package or recipe, I always use a 13x9 recipe and I line my baking pan with parchment paper so I can pull it out easily to cool. If brownies aren't thoroughly cooled, the frosting will melt.
Cream butter and powdered sugar together.
Mix in vanilla pudding and half & half until well blended.
Add peanut butter, mix until smooth.
Scrape down sides frequently during all steps.
Spread over cooled brownies.
Recipe by southerngirlsecrets.com at https://southerngirlsecrets.com/2012/09/05/gameday-goodies/