Thaw puff pastry on the counter for 30 minutes if frozen. Preheat the oven to 400 degrees F and line a baking sheet with parchment paper.

Roll out the puff pastry on a lightly floured surface to ensure even thickness without thinning it out.

Use bat cutters to cut out bat shapes from the puff pastry, ensuring to have an even number of each size for pairing.

Use the smallest bat cutter to remove the center from half of the large bats and half of the small bats.

Lay the bottom layer of bat shapes on a parchment-lined baking sheet and brush lightly with egg wash.

Carefully place the top layers with cut-outs onto the bottom layers, matching up the edges.

Brush the top layer with egg wash.

Bake in the preheated oven for 12 minutes, or until golden brown.

Gently press down the center of each bat to create space for filling.

Dust lightly with powdered sugar.

Optional: Fill the center of each bat with warmed blueberry jam using a piping bag or a small spoon.