Preheat the oven to 350°F (175°C).

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

Add the watermelon puree and vanilla extract, mixing well.

In a separate bowl, combine the flour and baking powder, then gradually add to the wet ingredients.

Mix until a dough forms.

Roll out the dough and use a cookie cutter to cut out watermelon slice shapes.

Place the cookies on a baking sheet and bake for 10-12 minutes or until lightly golden.

Let the cookies cool completely before decorating.

Use green icing to outline the edges of the cookies.

Fill in the center with red icing.

Add chocolate chips as seeds.