Cream butter, sugar and peanut butter until well combined. Add in vanilla. Sprinkle flour and salt on top of mixture, then stir until incorporated. Stir in Reese's Pieces.
Turn dough onto a piece of parchment paper (or wax paper) and fold paper over so that it covers the top of the dough. Roll dough out until about 1/2" thick. Use a small Easter Egg cookie cutter to cut eggs out of the dough, setting eggs on a parchment covered baking pan. Roll dough again as needed, until all dough has been shaped into eggs. (I have this 18-piece Wilton Spring cookie cutter set- I love it and that's where I got my 2 1/2" egg cookie cutter from.)
Freeze peanut butter eggs for 30 minutes.
Melt the chocolate, separating 2-3 TBSP of each, white and dark melting chocolate into small bags with the corners cut, for drizzling. I love using Chocoley Dipping & Coating Chocolate because it’s super easy to use and it tastes fantastic. (not like wax!) The trick to melting chocolate in the microwave is to go slowly and stir gently- and just before you feel like it's completely melted, take it out of the microwave and let it finish melting in the warm bowl. This time I used the large tubs of Chocoley Dipping chocolate, which are so handy! I melted them for 2 minutes, then stirred gently and warmed for another 30 seconds, then they were ready. I can re-use the tubs and bonus- no having to wash dishes!
If you'd rather use white & semi-sweet chocolate chips, combine 1 cups of each with 2 tsp coconut oil or shortening, to smoothen the chocolate and thin it out a bit so that it's easier to dip eggs. Microwave for 1 minute, then add time in 20 second increments until chips appear nearly melted, then let melt the rest of the way in the warm bowl.
Use a fork or a handy Winton Dipping tool like I did to dip each peanut butter egg in the chocolate, then shake gently to remove any excess. Transfer chocolate coated eggs to parchment or wax paper to cool. Immediately drizzle opposite color of chocolate on top of each egg and sprinkle with your favorite Easter sprinkles. Let cool to harden.
Store eggs in an airtight container. No need to refrigerate, unless you're making them 1-2 weeks ahead of time, then I'd store them in the fridge until you're ready to serve them.
*If you're nervous about consuming raw flour, I suggest you toast it beforehand! Simply spread flour out on a baking sheet and cook for 5 minutes at 350 degrees F. Cool completely, then proceed with the recipe. Other options are to use oat or almond flour in it's place.