Preheat the oven to 350°F (175°C).

In a mixing bowl, cream together the butter and granulated sugar until light and fluffy.

Add the vanilla extract and egg to the butter mixture and beat until well combined.

In a separate bowl, whisk together the flour, baking powder, salt, and pumpkin spice.

Gradually add the dry ingredients to the wet mixture and mix until a dough forms.

Roll the dough out on a floured surface to about 1/4 inch thickness.

Use a pumpkin-shaped cookie cutter to cut out shapes and place them on a baking sheet.

Bake the cookies for 8-10 minutes or until the edges are lightly golden.

Remove from the oven and let them cool on a wire rack.

To prepare the royal icing, beat together powdered sugar, meringue powder, and water until stiff peaks form.

Divide the icing into bowls and add food coloring as desired.

Transfer the icing to a piping bag and decorate the cooled cookies.