Soften the butter, then beat it together with the peanut butter in a medium bowl. Gradually beat in powdered sugar. Mixture may be crumbly, so knead it together a few times with your hands to bring it together.
Scoop out just under two tablespoons of peanut butter mixture and roll it into a ball. Flatten it slightly and tap it into an egg shape. Place on a parchment paper lined cookie sheet.
Chill the peanut butter centers until firm – about an hour in the fridge or 5-10 minutes in the freezer. Do not leave in the freezer too long – you want them chilled and firm, not frozen.
Melt the chocolate in the microwave in 30 second intervals, stirring thoroughly between microwaving. Heat until just melted; do not overheat.
Dip each peanut butter egg in the melted chocolate to coat it, then place back on the cookie sheet lined with parchment paper. If chocolate starts to harden, microwave for another 15 seconds to warm it back up.
Place dipped peanut butter balls into the fridge for about 10 minutes to set the chocolate. Check the bottoms and add more melted chocolate if needed to cover any bare spots. Also drizzle melted chocolate across the top to decorate and add sprinkles if desired. Return to the fridge for a few minutes until completely set.
Store at room temp for up to 2 days, or longer in the fridge.