Using a 3-inch flower-shaped cutter, cut 18 shapes from frozen bread slices, discarding scraps. Set 12 bread shapes aside. Using a 1 ½-inch flower-shaped cutter, cut a shape from centers of remaining 6 bread shapes, discarding centers. Cover all bread shapes with damp paper towels, or store in a resealable plastic bag to thaw and prevent drying out.
In a small bowl, combine cream cheese and confectioners’ sugar, stirring until smooth. Transfer cream cheese mixture to a piping bag fitted with a small star tip (Wilton #18).
Spread an even layer of peanut butter onto each of 6 solid bread shapes. Pipe a layer of cream cheese mixture on top of peanut butter layer, following the contours of the bread shapes. Top each with a solid bread shape. Spread an even layer of grape jelly onto each stack. Top each with a flower shape with cutout.
Cover with damp paper towels, and let bread thaw completely (approximately 30 minutes) before serving.
Recipe by TeaTime Magazine at https://teatimemagazine.com/creamy-pbj-triple-stacks/