Preheat your oven to 425°F (220°C) and line a baking sheet with parchment paper.
In a mixing bowl, combine the flour, baking powder, salt, garlic powder, and Italian seasoning. Stir until well mixed.
Gradually add enough water (about ½ cup) to the dry ingredients until the dough comes together. Knead the dough on a floured surface for a few minutes until smooth.
Roll out the dough to about ¼ inch thick. Use the skull-shaped cookie cutter to cut out skull shapes, making sure to have an equal number of tops and bottoms.
On half of the skull shapes, place a spoonful of pizza sauce, a sprinkle of mozzarella cheese, and your choice of toppings. Leave some space around the edges to seal.
Place the other half of the skull shapes on top and press the edges to seal. You can use a fork to crimp the edges for extra decoration.
Beat the egg in a small bowl and brush the egg wash over the top of each skull for a golden finish.
Place the assembled skulls on the prepared baking sheet and bake in the preheated oven for about 12 to 15 minutes or until golden brown.
Remove from the oven and allow to cool slightly before serving.