Heat a skillet over medium heat and add the ground meat. Brown for about 5-6 minutes, then stir in taco seasoning and any optional vegetables. Cook for an additional 2-3 minutes.

Roll out the refrigerated pie crusts on a floured surface. Use ghost-shaped cookie cutters to cut out top and bottom shapes and place them on a lined baking sheet.

On half of the ghost-shaped cutouts, spoon an even layer of taco filling and sprinkle shredded Mexican cheese on top.

Top each filled ghost with a matching cut-out and crimp the edges with a fork. Cut small slits in the tops to allow steam to escape.

Whisk an egg with a tablespoon of water to create an egg wash. Brush the mixture over the top of each pie.

Preheat the oven to 425°F (220°C) and bake the pies on the middle rack for 10-14 minutes until golden brown.

Allow the pies to cool slightly before serving warm with salsa or guacamole for dipping.