In a large bowl, beat peanut butter, butter and vanilla until blended.
Gradually beat in confectioners' sugar and cracker crumbs.
Shape mixture into 16 eggs; place on waxed paper-lined baking sheets.
Chill 30 minutes or until firm.
On low heat, melt chocolate chips and shortening; stir until smooth.
Dip eggs in chocolate mixture; allow excess to drip off.
Return eggs to baking sheets.
Chill 30 minutes.
If desired, decorate eggs with icing.
Let stand until fully set.
Store in airtight containers in refrigerator.